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Main Body Section

Specifications
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-1-01-00-41 1
1/6
Complete Machine Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-1-01-01-42 7
Standard Arm (3.20 m) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Short Arm (2.67 m) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/2
Long Arm (3.66 m). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Work Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-1-01-02-42 9
Standard Arm (3.20 m) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/3
Short Arm (2.67 m) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/3
Long Arm (3.66 m). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Optional Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-1-01-03-16 12
List of Optional Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/1
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Major Equipment Specifications

Equipment Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-00-11 13
Overall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Operator’s Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Lower Mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-01-39 15
Assembly Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/3
Travel Unit (with parking brake). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Take-up Roller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Upper Roller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Lower Roller (external roller) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Recoil Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Shoes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Upper Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-02-38 18
Swing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/1
Engine and Related Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-03-39 19
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/3
Muffler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Air Cleaner (double element). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Radiator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Fuel Tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Hydraulic System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-04-40 22
Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/3
Sump Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
Rotating Joint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Solenoid Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/3
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-05-41 25
Remote Control Valve (left/right, travel operations). . . . . . . . . . . . . . . . . . . . . . . .1/2
Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Backhoe Attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-2-01-06-41 27
Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Attachments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
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Hydraulics Section
Hydraulic Pump 290-1-02-01-16 29
1. Structure and Principle of the Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Control Valve 300-1-02-02-06 31
1. Operation with All Spools in Neutral Position . . . . . . . . . . . . . . . . . . . . . . . . .1/10
2. Separate Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/10
Swing Unit 300-1-02-03-05 41
1. Configuration of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/5
2. Structure of Hydraulic Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/5
3. Operational Description of Hydraulic Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/5
4. Operational Description of Mechanical Brake. . . . . . . . . . . . . . . . . . . . . . . . . .2/5
5. Operational Description of Make-up Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/5
6. Operational Description of Relief Valve
(Internal structural dawing of relief valve) . . . . . . . . . . . . . . . . . . . . . . . . . .3/5
7. Operational Description of Bypass Valve
(Internal structural drawing of bypass valve) . . . . . . . . . . . . . . . . . . . . . . . .3/5
Internal Structural Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/5
Internal Structural Drawing of Externally Adjusted Shockless Relief Valve . . . . . . . .5/5
Internal Structural Drawing of Bypass Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/5
Travel Unit
Travel Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300-1-02-04-06 46
1. Structural Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/7
2. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/7
3. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/7
Brake Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300-1-02-04-08 53
1. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/5
2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/5
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Hydraulic Circuits Section

Port Locations 290-1-03-00-18 58
1. Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
2. Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Pilot Hose Connection Diagrams 290-1-03-01-18 60
1. Pilot P&T Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/4
2. Pilot Control Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/4
List of Functions 290-1-03-02-17 64
List of Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Travel Circuits 290-1-03-03-13 66
1. High Speed Travel Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/6
2. Low Speed Travel Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/6
3. Straight Travel Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/6
Swing Circuits 290-1-03-04-14 72
1. Swing Parking Circuit (Lever in Neutral / Swing Locked) . . . . . . . . . . . . . . . . . . .1/6
2. Swing Parking Circuit (with Brake Released) . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/6
3. Swing Push Digging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/6
Arm Circuits 290-1-03-06-13 78
1. Arm-Out Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/6
2. Arm-In Load Holding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/6
3. Arm-In Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/6
Boom Circuits 290-1-03-07-13 84
1. Boom-Up Circuit (Single) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/8
2. Boom-Up Circuit (Combined). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/8
3. Boom-Down Load Holding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/8
4. Boom-Down Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7/8
Backup Circuit 290-1-03-09-11 92
1. Combined Circuit (Breaker Circuit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/4
2. Combined Circuit (High Speed Confluence Circuit). . . . . . . . . . . . . . . . . . . . . . . .3/4
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Electric Circuits Section

Description of functions 290-1-04-01-18 96
1. System Chart of Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/36
2. Engine Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/36
3. Operation Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6/36
A. Controls in H/S/L modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8/36
B. Controlling auto-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10/36
4. Throttle Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11/36
5. Idling Control (Auto/One-touch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12/36
6. Breaker Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14/36
7. Auto Preheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15/36
8. Auto Warm-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18/36
9. Idling Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19/36
10. Engine Emergency Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20/36
11. Limp-home Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21/36
12. Lever Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24/36
13. Auto Boost Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25/36
14. Swing Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26/36
15. Swing Brake Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26/36
16. Travel Speed Switch-over . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28/36
17. Travel Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30/36
18. Delayed Power Shut-off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31/36
19. Power Transistor Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32/36
20. Monitor Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33/36
Service Support 300-1-04-04-02 132
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/12
2. Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/12
Measuring the Electrical Devices 290-1-04-02-10 144
1. Instruments to be Measured . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/10
2. Equipment for Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/10
3. Measuring Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/10
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Initial Controller Settings 300-1-04-05-02 154

1. Verifying the Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
2. Resetting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
3. Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
4. List of Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
5. Error Display Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Troubleshooting 300-1-04-06-03 156
1. Problem Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/13
2. Inspections Prior to Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/13
3. Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3/13
4. Using the Flow Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/13
5. Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/13
A. Refilling fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5/13
B. Refilling coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6/13
C. Low engine oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7/13
D. Overheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8/13
E. Battery charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10/13
F. Faulty electrical system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11/13
G. Engine controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13/13
Electric Wiring Diagrams 290-1-04-07-15 169
Electrical Components and Wiring for Upper Frame . . . . . . . . . . . . . . . . . . . . . . .1/2
Electrical Components and Wiring for Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Harness Diagrams 290-1-04-08-15 171
Upper Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Inside Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
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Maintenance Section
New Machine Performance
Performance Evaluation Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000-3-02-00-13 173
1. Perfoarmance Evaluation Check Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
2. Performance Evaluation Recording Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/2
Reference Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290-3-02-01-16 175
1/1
Main Body Weight 290-3-01-00-39 176
1. Major Component Weight (Standard specifications) . . . . . . . . . . . . . . . . . . . .1/3
2. Individual Part Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
3. Shoe Weight (One side) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/3
4. Arm Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/3
5. Bucket Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/3
Attachments Dimensions 290-1-05-04-13 179
1/1
Instructions for Measuring and Adjusting Pressure 290-1-05-00-19 180
1. Measuring Pressure
A. Basic conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/14
B. Set values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/14
C. Pressure measuring port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2/14
D. Preparation for measuring pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4/14
E. Measuring pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6/14
F. Measuring other pressures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8/14
2. Adjusting Pressure
A. Pressure Adjusting Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9/14
B. Instructions for Adjusting Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11/14
Compatibility 290-1-05-05-16 194
List of Compatibility of Main Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2
Appendix
Unit Conversion Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300-1-08-01-02 196
1/1
New Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300-1-08-02-02 197
Long-life hydraulic oil (IDEMITSU Daphne Super Hydro 46SX) . . . . . . . . . . . . . . 1/1

Circuit diagrams (located inside the pocket at back of back cover)

Hydraulic Circuit Diagram (A1)
Electric Circuit Diagram (A1)
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Specifications

SH290-3

1. Main data:
Model name SH290-3 Hydraulic Excavator
Operating weight 28,400 kg
Engine output 132.4 kW / 2,200 min-1
Bucket capacity Heaped 1.10 m3
Leveled 0.76 m3

2. Performance
Standard weight 13.5 kN
Swing speed 10.4 min-1
Travel speed Low Speed 3.0 km/h
High Speed 5.1km/h
Maximum drawbar pull 219 kN
Grade ability 70% (35°)
Ground pressure 54 kPa

3. Complete machine dimensions

Standard arm Short arm Long arm
(3.20 m) (2.67 m) (3.66 m)
Length 10,410 mm 10,420 mm 10,430 mm
Width 3,200 mm 3,200 mm 3,200 mm
Height 3,270 mm 3,270 mm 3,480mm

4. Main body dimensions

Main body length 5,615 mm
Main body width 3,200 mm
Upper swing body width 2,750 mm
Cab width 1,000 mm
Main body height 3,050 mm
Tail swing radius 3,180 mm
Distance of rear swing body 3,180 mm
Ground clearance for upperstructure 1,200 mm
Center-to-center of wheels 3,930 mm
Overall track length 4,870 mm
Maximum track width 3,200 mm

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SH290-3

Center-to-center for track 2,600 mm

Width of track shoe 600 mm
Minimum ground clearance 490 mm (to bottom of lower frame)

5. Engine
Name ISUZU, CC-6BG 1T
Type Water-cooled, 4-cycle, 6-cylinder in line, direct
injection (electric control) turbo-charged diesel engine
with charge air cooler.
No. of cylinders – bore x stroke 6 – dia. 105 mm x 125 mm
Cylinder capacity 6,494 cc
Maximum torque 600 N·m / 1800min-1
Starter 24 V 4.5 kW
Alternator 24 V 50 A AC type
Battery 12 V 112 Ah (2)

6. Hydraulic system
Hydraulic pump drive system Directly-coupled to motor (no transmission)
Hydraulic pump
Model Double variable displacement piston pump (1)
Gear pump (1)
Discharge Piston pump: 2 x 221 L/min
Gear pump: 22 L/min
Pump control method Simultaneous total output horsepower control
Set pressure of main relief valve 34.3 MPa (power boost 37.3 MPa)
Set pressure of overload relief valve 39.2 MPa

7. Control valve
Model 4-spool section: integrated (1) or
5-spool section: integrated (1)
Operation method Hydraulic pilot method: travel, swing and operating machine

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SH290-3

8. Cooling system
Fan type Diameter 650 mm, 7 blades, air intake
Radiator
Capacity 96.5 KJ/s
Fin type Wavy
Fin space 2.0 mm
Oil cooler
Capacity 50.7 KJ/s
Fin type Wavy
Fin space 2.0 mm
Air-cooler
Capacity 22.3 KJ/s
Fin type Triangular straight
Fin space 2.0 mm

9. Operating devices
Operator’s seat
Location Left side
Structure Forward-backward and up-down adjustable type with
reclining mechanism and seat suspension
Cab Steel made enclosure type, reinforced glass (all sides)
Levers and pedals
For travel use Levers and pedals (hydraulic pilot type) (2)
For operating machine use Levers (hydraulic pilot type) (2)
Instruments and switches
Operation mode switchover 4 modes (heavy digging, standard, finishing and auto)
Travel speed switchover Low Speed / High Speed panel switch
One-touch idle Knob switch type
Monitor device
Machine status display (full-dot liquid
crystal)
Travel speed selection status Low Speed / High Speed
Operation mode selection status H/S/L/A
Auto idle selection status ON/OFF

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SH290-3

Instruments (full-dot liquid crystal,

except for hour meter)
Fuel gauge Bar graph indicator
Engine coolant temperature
gauge Bar graph indicator
Hydraulic oil temperature gauge Bar graph indicator
Hour meter Digital type

Machine Status and Warning Alarms (full-dot liquid crystal and warning tone)
*Items have a warning alarm
Over heat* Abnormal battery charging* Fault in electrical system*
Refill fuel* Engine oil pressure* Add coolant*
Engine preheat Automatic warm-up
Idling Service interval

Lighting
Work lamp Tank front side: 24 V 70 W (1)
Above boom: 24 V 70 W (1)
Interior light 24 V 10 W (1)
Horn Electric horn (2)
Other Wiper with intermittent function (1)
Window washer fluid (1)
Rear view mirror (right-hand side) (1)

10. Swing unit

Swing circle Swing bearing type (with internal gears)
Swing hydraulic motor Fixed displacement piston motor (1)
Reduction gears Planetary gear 2-speed reduction system
Swing parking brake Mechanical lock (operational lever linkage type)
Swing lock Mechanical lock (swing lock switch linkage type)

11. Travel lower body

Travel hydraulic motor Variable displacement piston motor (2)
Reduction gears Planetary gear 3-speed reduction system
Travel brake Hydraulic lock
Parking brake Mechanical lock (travel lever linkage type)

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SH290-3

Track shoe
Model Assembly-type triple grouser shoe
Number of shoes (per side) 47
Shoe width 600 mm
Grouser height 36 mm
Link pitch 216 mm
Roller
Number of upper rollers (per side) 2
Number of lower rollers (per side) 8
Track belt tension adjuster Grease cylinder type (with cushion spring)

12. Work Unit

Model Backhoe attachment
Capacity / dimensions / working
dimensions:
Bucket capacity Heaped 1.10 m3 (leveled 0.76 m3)
Bucket width 1,230 mm
Width of bucket with side cutter 1,330 mm
Weight of bucket with side cutter 850kg
Boom length 6,150 mm
Standard arm Short arm Long arm
(3.20 m) (2.67 m) (3.66 m)
Arm length 3,200 mm 2,670 mm 3,660 mm
Bucket wrist radius 1,600 mm 1,600 mm 1,600 mm
Bucket wrist angle 176° 176° 176°
Maximum dig radius 10,720 mm 10,290 mm 11,180 mm
Maximum dig radius at groundline 10,540 mm 10,100mm 11,000 mm
Maximum dig depth 7,130 mm 6,600 mm 7,590 mm
Maximum vertical straight wall dig
depth 6,040 mm 5,660 mm 6,650 mm
Maximum reach height 10,100 mm 10,010 mm 10,390 mm
Maximum dump height 7,090 mm 6,970 mm 7,360 mm
Minimum swing radius at front 3,900 mm 4,000 mm 3,930 mm
Overall height with minimum swing
radius at front 8,170 mm 8,170 mm 8,150 mm

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SH290-3

13. Hydraulic Cylinder Inner Rod

Quantity × diameter − diameter − Stroke
of tube
Boom cylinder 2 × dia. 135 mm − dia. 95 mm − 1,369 mm
Arm cylinder 1 × dia. 150 mm − dia. 105 mm − 1,438 mm
Bucket cylinder 1 × dia. 130 mm − dia. 90 mm − 1,073 mm

14. Digging force (new JIS) Standard arm Short arm Long arm
(3.20 m) (2.67 m) (3.66 m)
Bucket digging force
(Standard / Power boost) 160 kN / 173 kN 160 kN / 173 kN 160 kN / 173 kN
Arm digging force
(Standard / Power boost) 115 kN / 125 kN 126 kN / 140 kN 100 kN / 108 kN

15. Capacity of coolant and lubricants

Coolant 29 L
Fuel 340 L
Lubricant for engine 24 L
Lubricant for travel reduction gear
(per side) 4.7 L
Lubricant for swing reduction gear 6L
Hydraulic oil 240 L
Capacity of hydraulic oil tank 120 L

16. Hydraulic oil filter

Suction filter (inside tank) 105 mesh
Return filter (inside tank) 10 µm
Nephron filter (inside housing) 1 µm
Pilot line filter (inside housing) 10 µm

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Complete Machine Dimensions

Standard Arm (3.20 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram include the lug height of shoe (36 mm).

Complete Machine Dimensions

Short Arm (2.67 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram include the lug height of shoe (36 mm).

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Complete Machine Dimensions

Long Arm (3.66 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram include the lug height of shoe (36 mm).

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Work Range
Standard Arm (3.20 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram exclude the lug height of shoe (36 mm).

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Work Range
Short Arm (2.67 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram exclude the lug height of shoe (36 mm).

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Work Range
Long Arm (3.66 m)
Note 1: Numerical values may be changed without notice due to design alterations or other reasons.
Note 2: The values in the diagram exclude the lug height of shoe (36 mm)

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Optional Components
List of Optional Components
Standard Optional

Specifications SH290-3

600 G Shoe

700 G Shoe

800 G Shoe

Track Guard (Single)

Lower Under Cover

Water Separator

Fuel Pre Filter

Air Cleaner (Double Element)

Spare Valve

Breaker Circuit

Compatible Circuit

Spare Relief Valve

Tilt Open Rear Window

Seat Belt

Heater

Air Conditioner

Face Blower

Defroster

AM/FM Radio

Travel Alarm

12V Power Supply

Fuel Feed Pump

Dog Chain

Semi E.M.S (ATT)

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Equipment Configuration
Overall

200
SH

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Operator’s Cab

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 290-2-01-01 -39
Lower Mechanism
Specifications Page No. 1/ 3 Assembly Diagrams
MAJOR EQUIPMENT SPECIFICATIONS First Edition: 09/2004

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MAJOR EQUIPMENT SPECIFICATIONS First Edition: 09/2004

Travel Unit (with parking brake)

Sumitomo Part No. KBA1319
Manufacturer NABCO Ltd.
Motor type Variable displacement piston motor
(automatic 2-speed switch-over)
Displacement 244.3/141.1 cm3/rev
Operating pressure 34.3 MPa
Operating flow 216.8 L/min
Reduction gears
Reduction ratio 39.875
Parking brake
Brake torque 902 N·m or over (with reduction gear)
Brake valve relief pressure Cracking 35.8 to 37.2 MPa
Dry weight 365 kg

Take-up Roller
Sumitomo Part No. KSA1064
Weight 154 kg

Upper Roller
Sumitomo Part No. KBA1141
Weight 43.0 kg

Lower Roller (external roller)

Sumitomo Part No. KSA1068
Weight 60.0kg

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Recoil Spring
Item Sumitomo Part No.
Yoke KSA1065 39.8 kg

SEMS bolt M16x50 105R016Y050R 0.5 kg

Threaded rod KSA1066 50.3 kg

Nut with deep grooves M76x6 165R064HSN 1.9 kg

Spring pin 10x100 338W100Z100B 0.1 kg

Recoil spring KSA1297 102.4 kg

Grease assembly cylinder KSA0832 41.3 kg

SEMS bolt M16x65 105R016Y065R 0.3 kg

Assembly Total weight 240 kg

Mounting length of spring: 779 mm

Shoes
Sumitomo Part No.
600 Grouser KBA10020 2,191 kg
Link KBA10050 One set
Shoe KSA1121 47
Bolt KSA1122 188
Nut KSA1123 188

Sumitomo Part No.

700 Grouser KBA10030 2,387 kg
Link KBA10050 One set
Shoe KSA1173 47
Bolt KSA1122 188
Nut KSA1123 188

Sumitomo Part No.

800 Grouser KBA10040 2,595 kg
Link KBA10050 One set
Shoe KSA10060 47
Bolt KSA1122 188
Nut KSA1123 188

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Upper Mechanism
Swing Unit
Item Specifications
Motor type Fixed displacement piston motor (1)
Reduction gear type Planetary gear 2 speed reduction system
Type of swing parking brake Mechanical lock (swing lever/swing lock switch
linkage type)

Sumitomo Part No. KBC0120

Manufacturer TOSHIBA MACHINE CO., LTD.
Motor type Fixed displacement piston motor
Displacement 164.7 cm3/rev
Operating pressure 29.4 MPa
Relief set pressure 29.3 ± 0.4 MPa at 100 L/min
Reduction gears
Reduction ratio 27.143
Swing brake
Brake torque 849 N·m or over
Brake release pressure 2.9 MPa
Dry weight 428 kg

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Engine and Related Areas

Engine
Sumitomo Part No. KBH1010
Engine model name ISUZU 6BGIT Diesel Engine
Engine type 4-cycle, water-cooled, in-line, direct-injection
(electroric control)
Number of cylinders – Bore x Stroke 6 - dia. 105 mm × 125 mm
Displacement 6.494 L
Compression ratio 18.0
Rated output 132.4 ± 2.2 Kw / 2,200 min-1
Maximum torque 600 N·m / approx.1,800 min-1
Dry weight Approximately 487 kg
Engine dimensions L 1206 × W 814.6× H 996 mm
Oil pan All direction 35°, inclinable
Cooling fan 7 blades, suction type, 650 mm in dia., resin;
with bell-mouth type fan guide
Pulley ratio 0.88 (reduction)
Alternator 24 V × 50 A AC type
Starter-generator 24 V × 4.5 Kw reduction type
Coolant capacity 12.0 L (engine only)
Oil pan capacity Maximum: 21.5 L Minimum: 16.4 L (excluding oil
filter)
Direction of rotation Right (viewed from fan side); compliant with
Conditions for rated output JIS D 0006-1994
With fan and generator
Without muffler and air cleaner

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Muffler
Sumitomo Part No. KBH0893
Manufacturer TOUEI INDUSTRIAL Co., Ltd.
External dimensions dia. 280 × 770 mm
Weight 16.0 kg

Air Cleaner (double element)

Sumitomo Part No. KBH0886
Element (outer) KBH0921
Element (inner) KBH0922
Manufacturer NIPPON DONALDSON LTD.
Weight 5.7 kg

Radiator
Sumitomo Part No. KBH0890
Manufacturer TOYO RADIATOR CO., LTD.
Oil cooler Weight 34.0 kg
Oil capacity 15.7 L
Radiator Weight 50.0 kg
Water capacity 20.0 L
Air cooler Weight 18.0 kg
Total weight 165 kg

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Fuel Tank
Specifications Page No. 3/ 3

MAJOR EQUIPMENT SPECIFICATIONS First Edition: 09/2004

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Hydraulic System
Hydraulic Pump
Sumitomo Part No. KBJ2895
Manufacturer Kawasaki Precision Machinery Ltd.
Type Double variable displacement piston pump (1)
Displacement 97.2 cm3/rev × 2
Rated operating pressure 34.3 MPa
Maximum operating pressure 37.3 MPa
Maximum flow 217 × 2 L/min at 2,230 min-1
Pilot pump
Type Fixed displacement gear pump (1)
Displacement 10 cm3/rev
Operating pressure 3.92 MPa
Maximum flow 22.3 L/min at 2,230 min-1
Dry weight 139 kg

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Sump Tank
Specifications Page No. 2/ 3

MAJOR EQUIPMENT SPECIFICATIONS First Edition: 09/2004

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Rotating Joint
Sumitomo Part No. KRA1875
Operating pressure
High pressure passage (ABCD) 34.3 MPa
Pilot port (F) 3.9 MPa
Drain port (E) 0.5 MPa
Hydrostatic test pressure
High pressure passage (ABCD) 51.5 MPa
Pilot port (F) 5.9 MPa
Drain port (E) 1.0 MPa
Flow
High pressure passage (ABCD) 212.2 L/min
Pilot port (F) 21 L/min
Drain port (E) 10 L/min
Number of revolutions 15 min-1
Torque When pressurizing 2 ports 147 N·m
Hydraulic oil used ISO VG46
Range of hydraulic oil temperature -20 to +95°C
Port A Forward right G1/2-A Class
Port B Forward left G1/2-A Class
Port C Backward right G1/2-A Class
Port D Backward left G1/2-A Class
Port F Pilot port G1/4-A Class
Port E Drain port G1/4-A Class
Weight 29.2 kg

Solenoid Valve
Sumitomo Part No. KRJ6304
Manufacturer Uchida Hydraulics Co., Ltd.
Valve specifications
Maximum flow P→B: 20 L/min Other: 5 L/min
Rated pressure 4.41 MPa
Solenoid specifications
Operating voltage DC 20 to 32 V
Current 13.0 W (at 24 V, 20°C)
Weight 6.0 kg

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Controls
Remote Control Valve (left/right, travel operations)
Valve for Left/Right Operations
Sumitomo Part No. KRJ5804
Manufacturer Kawasaki Precision Machinery Ltd.
Operating pressure 3.92 MPa
Secondary pressure 0.64 ± 0.1 to 2.45 ± 0.14 MPa: Primary short type
Operating angle Ports 1, 3 19 ± 1.9°
Ports 2, 4 25 ± 2.5°
Operating torque Port 1 1.18 to 2.67 N·m
Port 3 0.94 to 2.38 N·m
Ports 2, 4 1.37 to 3.19 N·m
Hydraulic oil ISO VG46
Operating temperature range 253 to 368K (-20 to 95°C)
Weight 1.8 kg

Valve for Travel Operation

Sumitomo Part No. KRJ5803
Manufacturer Kawasaki Precision Machinery Ltd.
Oparating pressure 3.92 MPa
Secondary pressure 0.64 ± 0.1 to 2.45 ± 0.14 MPa: Primary short type
Operating angle 12.4 ± 0.3°
Operating torque 4.16 to 10.6 N·m
Valve damper 4.90 ± 0.98 N·m at 0.0275 m/s
Hydraulic oil ISO VG46
Operating temperature range 253 to 368 K (-20 to 95°C)
Weight 7.8 kg

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Control Valve
Sumitomo Part No. KBJ3023
Manufacturer KAYABA INDUSTRY Co., Ltd.
Maximum flow 217 L/min
Pressure setting for overload 39.2 ± 0.5 MPa
Pressure setting for main relief 34.3 ± 0.3 MPa
37.3 ± 0.5 MPa (at boosting)
Operating temperature range -20 to +95°C
Pressure setting for foot relief 2.55 +0.3
0 MPa at 50 L/min
Functions Straight travel circuit
Boom UP; 2-speed, internal confluence for Arm
Boom/arm load holding circuit
Boom down regenerative circuit
Arm IN forced regenerative circuit
Variable throttle valve in the parallel circuit at arm
Swing priority variable throttle valve
Preliminary 2-speed confluence
Weight 187 kg

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Backhoe Attachments
Cylinder
Boom Cylinder R/L
Sumitomo Part No. KBV1688 / KBV1689
Manufacturer KAYABA INDUSTRY Co., Ltd.
Cylinder bore dia. 135 mm
Rod diameter dia. 95 mm
Max. retracted length 1,918 ± 3.0 mm
Stroke 1,369 ± 2.0mm
Dry weight 235 kg

Arm Cylinder
Sumitomo Part No. KBV1897
Manufacturer KAYABA INDUSTRY Co., Ltd.
Cylinder bore dia. 150 mm
Rod diameter dia. 105 mm
Max. retracted length 2,071 ± 3.0 mm
Stroke 1,438 ± 2.0mm
Dry weight 335 kg

Bucket Cylinder
Sumitomo Part No. KBV1790
Manufacturer KAYABA INDUSTRY Co., Ltd.
Cylinder bore dia. 130 mm
Rod diameter dia. 90 mm
Max. retracted length 1,665 ± 3.0 mm
Stroke 1,073 ± 2.0mm
Dry weight 194 kg

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Attachments
Standard bucket
For general digging (specific gravity: 2.0 ton/m3 or less)
For light digging (specific gravity: 1.6 ton/m3 or less)
∆ For loading only (specific gravity: 1.2 ton/m3 or less)
x Do not use

Bucket Capacity (m3) 1.0 1.1 1.3

Number of teeth 5 5 5
1,255 1,331 1,511
Width (mm)
(1,175) (1,230) (1,410)
Long arm
(3.66 m) ○ △

Type of arm Standard arm

○
specified (3.20 m)
Short arm
(2.67 m)

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HYDRAULIC PUMP First Edition: 09/2004

1. Structure and Principle of the Function

This pump is structured to couple two pumps with the spline connection. By transmitting the rotational force
from the engine to the front side drive shaft (111), the two pumps are forced to be driven. The ports for
adjusting and discharging oil are located in valve block; the hitch of two pumps, and the port for adjusting oil is
used for both front and rear pumps. As front and rear pumps have the same configuration and the same
principle of the function, the following explanation is for front pump.
This pump broadly consists of the rotary group which is the main part of the pump governing the rotational
motion, the swash plate group which adjusts the discharge rate, and the valve block group which switched the
intake and discharge of oil.
The rotary group consists of the drive shaft F (111), cylinder block (141), piston shoe (151, 152), retainer
(153), spherical bush (156), and cylinder spring (157). The drive shaft’s ends are supported by the bearing
(123, 124).
The shoe forms a spherical joint caulked by the piston. It contains a pocket area in order to reduce the thrust
force, which is generated by the loading pressure, and slide lightly on the shoe plate (211). The sub group of
the piston shoe is pressed on the shoe plate by the cylinder spring via the retainer and spherical bush in order
to move smoothly on the shoe plate. The cylinder block is also pressed on the valve plate (313) by the cylinder
spring.
The swash plate group consists of the swash plate (212), shoe plate (211), swash plate support (251), leaning
bush (214), leaning pin (531), and servo piston (532). The swash plate is supported on the swash plate
support by the cylindrical part formed on the opposite side of the shoe sliding side.
When the service piston moves to the right and left due to the regulator controlling hydraulic force being led to
the hydraulic compartment, the swash plate is able to swing the swash plate support and change the leaning
angle (a) via the spherical part of the leaning pin. The hydraulic compartment is located on the both sides of
the servo piston.
The valve block group consists of the valve block (312), valve plate (313), and valve plate in (885). The valve
plate which has two claw shaped ports installed on the valve block. If feeds and collects oil from the cylinder
block. Oil which is switched by the valve plate flows to the external pipe through the valve block.
When the drive shaft is driven by the motor (electric motor, engine, or others), the cylinder block rotates
simultaneously via the spline connection. If the swash plate is leaned, the piston located inside the cylinder
block rotates with the cylinder block and exerts the reciprocal motions in relation to the cylinder
correspondingly. Therefore, when focusing on one specific piston. In one full rotation, the piston moves toward
the direction which is leaving apart from the valve plate (process of intake oil) during the first 180 degrees, and
moves toward the direction which is coming to the valve plate (process of discharging oil) during the remaining
180 degrees. When the swash plate’s angle is 0 degrees, the piston does not stroke, and therefore, oil will not
be discharged.

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1. Operation with All Spools in Neutral Position

A. Neutral passage (Figures 1 and 2)
Oil supplied from Port P1 enters the tank passage Ta from neutral passage L1, passing the restriction Lc1
on the low pressure relief, and returns to Ports T1, T2, T3, T4 and T5.
Oil supplied from Port P2 passes the tank passage Ta through neutral passage R1, passing the restriction
Rc1 on the low pressure relief, and returns to Ports T1, T2, T3, T4 and T5.
Pressures in the pressure chambers L2 and R2 located in the upstream of the low pressure relief valve are
directed to the pump through Ports ps1 and ps2 and control the delivery volumes of pumps P1 and P2.
In addition, if a large amount of extra oil flows into the neutral passage, the low pressure relief mechanism
functions to prevent pressures on Ports ps1 and ps2 from increasing abnormally.
Figure 1
LOW PRESSURE LOW PRESSURE
RELIEF VALVE [L] RELIEF VALVE [R]

BACKU

P1 SIDE P2 SIDE

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Figure 2

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B. Signal passage (Figures 2 and 3)

Oil supplied from Port PP goes into Port PT through restriction Lc3. At the same time, it flows into the tank
passage Ta through the land Rc3, passing the land Lc4 and passage .
Part of the oil supplied from Port PP goes into Port PA through the restriction Lc5. It also flows into the tank
passage Ta through the bucket spool land Rc4, passing the passages L4, and R4.
The oil passed through the restriction Lc6 flows into the tank passage Ta through the land Lc7. It also
passes the passage and flows into the tank passage Ta through the travel spool land Rc5.
Figure 3

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2. Separate Operation
A. Travel spool switching (Figure 4)
When switching the travel spool by adding pressure through the Pilot Port Pb1 (Pa1) in Travel (Section 1,
the oil supplied from Port P1 flows into Port B1 (A1) passing the neck part of the spool via neutral passage
L1. The return oil passes the neck part of the spool via Port A1 (B1) and returns to the tank passage Ta.
When switching the travel spool by adding pressure through Pilot Port Pb6 (Pa6) in Travel (Section 6), the
oil supplied from Port P2 flows into Port B6 (A6) passing the neck part of the spool or passage S6-1 via
neutral passage R1. At this moment, because pressures on parallel passage R3 and passage S6-1 are
equal, the poppet S6-2 does not open. The return oil passes the neck part of the spool via Port A6 (B6)
and returns to the tank passage Ta.
When switching only one side of the spool in Travel (Section 1 or 6), Land Lc4 or Rc3 closes. Since the
flow of oil supplied from Port PP to the tank passage is shut off, the pressure on Port PT increases.
Figure 4

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B. Backup spool switching (Figure 4)

When switching the swing spool by adding pressure through Pilot Port Pb2 (Pa2) in Back-up (Section 2),
the neutral passage L1 closes. Oil supplied from Port P1 passes the load check valve S2-1, the passage
S2-2, and the neck part of the spool through the parallel passage L3 and flows into Port B2 A2.
The return oil passes the neck part of the spool via Port A2 (B2) and returns to the tank passage Ta.
If oil is supplied from Port P4, it passes the poppet S2-3 and merges at the passage S2-2.
Figure 4

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C. Swing spool switching (Figure 5)

When switching the swing spool by adding pressure through Pilot Port Pb3 (Pa3) in Swing (Section 3), the
neutral passage L1 closes. Oil supplied from Port P1 passes the load check valve S3-1, the passage S3-2,
and the neck part of the spool through the parallel passage L3 and flows into Port B3 (A3). The return oil
passes the neck part of the spool via Port A3 (B3) and returns to the tank passage Ta.
Figure 5

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D. Boom spool switching

1. Neutral Position (Figure 6)
This valve has an anti-drift valve installed on the cylinder bottom side of the boom 1. When being in
neutral position, the poppet AD1 is firmly seated by the pressure on Port A8 that is directed to the
spring chamber AD4 through the passage AD2 and spool AD3.
2. Boom UP (2 pump confluence) (Figure 7)
When switching the boom 1 spool by adding pressure through Pilot Port Pa8 in Boom 1 (Section 8),
neutral passage R1 closes. Oil supplied from Port P2 passes the parallel passage R3, the load check
valve S8-1, and the neck part of the spool, and flows into Port A8. When switching the boom 2 spool by
adding pressure through Pilot Port Pb4 also in Boom 2 (Section 4), the neutral passage L1 closes. Oil
supplied from Port P1 passes the parallel passage L3, the load check valve S4-1, the neck part of the
spool and passage (6), and merges and flows into Port A8. The return oil passes the neck part of the
spool via Port B8 and returns to the tank passage Ta.
3. Boom DOWN (Recycle) (Figure 8)
When switching the boom 1 spool by adding pressure through Pilot Port Pb8 in Boom 1 (Section 8), the
neutral passage R1 closes. Oil supplied from Port P2 passes the parallel passage R3, the load check
valve S8-1 and the neck part of the spool and flows into Port B8. When switching the spool AD3 in the
anti-drift valve by adding pressure to Port Pc2 and reducing the pressure in spring chamber AD4 at the
same time, the poppet AD1 opens and the return oil from Port A8 returns to tank passage Ta. Part of
the return oil pushes open the poppet S8-3 in boom 1 spool, passing the passage S8-2 and merging
into Port B8 to prevent cavitation on the cylinder rod side.
Figure 6

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Figure 7

Figure 8

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D. Arm spool switching

1. Neutral position (Figure 9)
This valve has an anti-drift valve installed on the cylinder rod side of Arm 1.
When in neutral position, the poppet AD1 is firmly seated by the pressure on Port A5 that is directed to
the spring chamber AD4 through the passage AD2 and spool AD3.
Figure 9

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2. Arm IN (2 pump confluence) (Figure 10)

When switching the arm 1 spool by adding pressure through Pilot Port Pb5 in Arm 1 (Section 5), the oil
supplied from Port P1 flows into Port B5 passing the load check valve S5-1, the passage S5-2 and the
neck part of the spool via the neutral passage L1. When switching the arm 2 spool by adding pressure
through Pilot Port Pb9 also in Arm 2 (Section 9), the oil supplied from Port P2 passes the load check
valve S9-1, the passage S9-2, the neck part of the spool, and the passage (10) and merges and flows
into Port B5.
The return oil from Port A5 passes the recycle check (XX-X) in the spool, and is then divided into two
flows: one goes for the recycling process at Port B5 and the other passes the recycle relief valve and
returns to the tank passage Ta.
Figure 10

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1. Configuration of Components

NOTE: Numbers in parentheses in the following text correspond to the circled numbers in the Internal
structural drawings.

2. Structure of Hydraulic Motor

The rotary component group is composed of a drive shaft integrated type cylinder (27) and nine piston
assemblies (8) arranged in the cylinder (27). Additionally, both ends of the cylinder (27) are supported with
bearings (4) and (25). Piston assemblies (8) are guided by return plates (6) and spring bearings (7) so that
they can slide on the cam plates (5) smoothly.
The balance plate (24) is pressed against the end face of cylinder (27) by the force of coned disc spring (17)
and hydraulic pressure acting on the bushing (15).
Mechanical brakes (9), (10), (11) and (14) that are used as parking brakes are installed between the
circumference of cylinder (27) and the housing (28).
Also, a relief valve (31) as cushion and makeup valves (35), (36) and (39) for preventing cavitation are built in
the cover section (29). In order to prevent swinging-back when swing operation is stopped, a bypass valve
(43) is integrated into the cover (29).

3. Operational Description of Hydraulic Motor

Hydraulic oil supplied from the pump via the control and other valves enters from Port A (or Port B) on the
cover (29) and is discharged from Port B (or Port A). Oil leaked from gaps in each sliding part is returned to
the tank through the drain Port “a” on the cover (29).
The pressurized oil supplied to Port A is supplied to the piston hole “f” in the cylinder (27), passing the
following components in order: passage “b” in the cover (29), passage “c” on the bushing (15) section on the
cover (29), passage “d” on the balance plate (24) which has a crescent-shaped port switching between supply
and discharge every 180° per one motor turn, as well as, passage “e” on the cylinder (27).
The oil pressure acts on piston assembly (8), resulting in piston assembly (8) being pressed to the cam plate
(5) via the shoe section. Because the sliding face of the shoe on cam plate (5) is inclined at a given angle, the
pressing force on the piston assembly (8) to which the oil pressure pushes, is transformed into a force that
slides the shoe on the swash plate. Because the spherical shoe section of piston assembly (8) is connected
so that it works as a universal joint, the shoe’s sliding force on the swash plate is transferred to the motor
output shaft as a turning force via the piston assembly (8) and cylinder assembly (27).

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As mentioned above, each piston assembly (8) receives the pressurized oil while it travels the stroke from the
top dead center to the bottom dead center of the incline plane and transforms it into a turning force to revolve
cylinder assembly (27) and discharges oil while it travels the stroke from the bottom dead center to the top
dead center. The discharge route is the reverse of the supply route described above and the oil is discharged
from Port B.
The hydraulic motor operates in the manner as described above. Its output torque and the number of
revolutions are determined according to the hydraulic force and the volume of oil supplied respectively.

4. Operational Description of Mechanical Brake

Friction plate (9) is connected to the circumference of cylinder assembly (27) via spline. Also, the counterpart
plate (10) is connected to the housing (28). When the pressure in the mechanical brake release chamber is
zero, the cylinder assembly (27) (output shaft) is locked and will not turn as a result of the brake piston (11)
pressing the counterpart plate (10) and friction plate (9) through the spring force (14).
In the opposite manner, when the oil pressure of 2.9 to 4.9 MPa is reached on the brake release chamber, the
brake piston (11) overcomes the force and moves until it hits the end face of the cover (29), creating space
between friction plate (9) and counterpart plate (10). As a result, the mechanical brake turns to a released
status.

5. Operational Description of Make-up Valve

A. Half-braking condition (a state where relief valve (31) is not in operation)
When decelerating the swing body through the control valve using the half-lever function after accelerating
the swing body, the supply volume to Port A from the pump decreases but it is necessary to supplement oil
when the swing body is rotating at a relatively high speed because the pressure applied to the “c” section
tends to become negative due to motor’s pumping action.
However, because the whole volume of oil which flows into “c” section from Port A is discharged into
control valve via Port B when the pressure on Port B is lower than the working pressure of relief valve (31),
the absolutely necessary oil volume at the “c” section is not met with the oil volume from the control valve
alone (as the valve is in the half-lever position, the oil volume is still restricted). To prevent this, makeup
check (39) is provided to supplement “c” section to make up for a lack of oil through the makeup port.
B. Full braking condition (a state where relief valve (31) is in operation)
When changing to the neutral position from condition A by quick lever operation, the swing body is turned
by inertial force even though the oil supply volume from the pump to Port A becomes zero. In this case,
relief valve (31) on the Port B side operates, and the oil, which blew off the relief, passes oil passages “g”
and “h”, presses open the makeup check (39) on Port A and is supplemented to the passages “b” and “c”.
However, the oil lacks by its volume that which has leaked into the case drain of the motor. To prevent this,
the makeup check (39) is opened from the makeup port and the oil flows into the passages “b” and “c” in
order to prevent cavitation.

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6. Operational Description of Relief Valve

(Internal structural drawing of relief valve)
A. When starting
The hydraulic oil supplied from Port A by operating the control valve does not immediately reach the
constant revolution level due to the large inertial force of the swing body. Part of the oil passes oil passages
“g” and “h” via relief valve (31) that works as a safety valve, presses open the check (39) on Port B side and
flows into Port B.
Oil in Port A presses open the poppet (47) by counteracting the force of spring (48), passes passage “g”
via a space between seat (46) and poppet (47) and flows into passage “h”.
B. When braking (at time of cushioning)
When the control valve is returned to the neutral position, the return passage for the motor’s drain oil
closes. Immediately after this operation, the motor is turned by large inertial force and attempts to suck oil
through Port A by pumping action and to discharge it to Port B. As a result, the pressure on Port B
increases because the return passage in the control valve is closed.
As the increased pressure on Port B presses open poppet (47) by counteracting the force of spring (48), the
oil flows into passage “c” by pressing open the makeup check (39) via oil passages “g” and “h” through Port
B. In this process, the inertial force of the swing body is absorbed and the swing body comes to a stop.
Also, in the pressure increasing process above mentioned, the highly pressurized oil that flowed into the
front chamber of poppet (47) enters the piston chamber passing the small hole passage on the central
section of piston (52) via circumferential orifice “j” of poppet (47) and moves piston (52) until it hits the end
face of sleeve (51). Meanwhile, since poppet (47) is already forcedly opened, the cushion relief begins to
work at relatively low pressure, and then increases to a specified pressure in minimal time. This dual-step
action decreases the impact of motor starts and stops.

7. Operational Description of Bypass Valve

(Internal structural drawing of bypass valve)
When attempting to stop the swing body after operating the control valve to drive the swing body, braking
pressure is generated on one side of the port as the hydraulic motor, which keeps rotating due to its inertial
force, continues its pumping action.
Suppose that this is Port A: This pressurized oil for braking flows into the back chamber of check (60) on
the Side A via small holes (a3) and (a2). As a result, the check (60) on Side A moves until it contacts and
presses seat (58) on Side A to shut off the bypass passage by pushing check (60) on Side B, which is
arranged as a counterpart, to the left in the process of decelerating the swing body. In due course, the
swing body stops once but reverses due to braking pressure. Therefore, the pressure on Side B increases
and check (60) on Side B attempts to move to the right by pushing check (60) on Side A, which is arranged
as a counterpart. However, this movement of check (60) is a little delayed because the oil flow of the back
chamber in check (60) on Side A is gently controlled through the action of the flow control valve comprised
of poppet (61) on Side A and spring (62) on Side A. In the meantime, the pressurized oil of Port B flows
into the intermediate chamber via small hole “b1” and bypasses Port A side via small hole “a1”.
Subsequently, check (60) on Side B contacts and presses seat (58) on Side B and moves to the position
where it can shut off the bypass passage. As described above, the reverse motion will be prevented
without any trapping of the oil because the pressure is bypassed to Port A side in the process of generating
reverse pressure on the Port B side.

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Internal Structural Drawing

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Internal Structural Drawing of Externally Adjusted Shockless Relief Valve

Internal Structural Drawing of Bypass Valve

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1. Structural Drawing

1. CASING 16. D RING (LARGE) 30. BEARING HR32209J

2. REAR COVER 17. CHECK VALVE 31. BEARING HR32207C
3. CYLINDER BLOCK 18. C-SHAPED SNAP RING (FOR HOLE 32. HEXAGONAL SOCKET HEAD BOLT
4. SHOE RETAINER USE) M18 X 50
5. FRICTION PLATE 19. CIRCULAR SNAP RING 33. SHIM
6. BRAKE PISTON 20. INCLINE PISTON 34. PARALLEL PIN 8 X 12
7. SEPARATOR PLATE 21. STEEL BALL 35. O-RING 1B P6
8. VALVE PLATE 22. PIVOT 36. O-RING 1B P8
9. SHAFT 23. PISTON SEAL 37. O-RING 1B P9
10. COUPLING 24. M6 RESTRICTION (0.6) 38. O-RING 1B S10
11. SHOE PLATE 25. M6 RESTRICTION (0.8) 39. O-RING 215.57 X 2.62
12. BALL JOINT 26. OIL SEAL 40. OVERLOAD VALVE ORV-240L6
13. SPRING BEARING 27. CHECK VALVE SPRING 41. PILOT VALVE MRC03
14. PISTON ASSEMBLY 28. CYLINDER SPRING 42. BRAKE VALVE RBV-24DL5
15. D RING (SMALL) 29. BRAKE SPRING 43. SPACER
44. O-RING 1B G35

Figure 1. Structural drawing of travel motor

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2. Structure
The main components for the motor include a rotary group which generates torque, a negative brake
preventing runaway when parking, a variable mechanism section which switches motor capacity between
large and small, and an overload valve which is integrated into the rear cover.
There is another valve that plays an important role to control the travel hydraulic circuit. It is called a brake
valve or counterbalance valve. For the functions of this valve, please refer to the brake valve section.
A. Rotary group
The cylinder block (3) is fitted into the tooth spaces of the spline on the shaft (9), of which both ends are
supported by bearings (30 and 31). The cylinder block (3) is pressed to the rear cover (2) together with the
valve plate (8) by the cylinder spring (28).
Nine units of piston assemblies (14) slide along the surface of the shoe plate (11) while coming into and
out of the cylinder block (3).
A bearing is provided on the end surface of the piston assembly (14) so that its sliding resistance is
reduced and so that it can slide without being apart from the surface of shoe plate (11). The force of the
cylinder spring (28) is transferred from the spring bearing (13) to the ball joint (12) to the shoe retainer (4),
resulting in the end surface of the piston assembly (14) to be pressed into the shoe plate (11).
B. Negative brake
Five sheets of separator plates (7) and 4 sheets of friction plates (5), which are alternately fitted into the
spline teeth on the circumference of the cylinder block (3), are pressed to the casing (1) by 14 pieces of
brake springs (29) via the brake piston (6).
C. Capacity variable mechanism section
This section is composed of the following components: Pivots (22), which are fitted into two spherical
cavities on two locations of the shoe plate (11) for support; an incline piston (20), which inclines the shoe
plate (11) around the pivot (22); an incline stopper (1-1), which maintains the set position for incline-rotation;
pilot valves (41), which direct hydraulic oil into the incline piston (20) through external command; and three
check valves (17), which take the highest oil pressure out of the three pressures (externally controlled pilot
pressure, motor entry pressure and motor exit pressure) and deliver it to the pilot valve (41).

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D. Overload valve
This valve is composed of the following components: a socket (40-1), which is fixed by screwing into the
rear cover (2) and which holds a metal valve seat (40-3) in the internal hole section on the rear cover (2)
of the motor; a valve (40-2), which is fitted into the internal hole of the socket and contacts the valve seat
(40-3) by the adjusting spring (40-9); the connecting piston (40-4), which is inserted into the internal valve
hole and functions as an oil passage to the pilot section body (40-6); a piston (40-7), which is inserted in
the pilot section body (40-6) and is pressed by the plug (40-5); and a shim (40-8), for adjusting a spring.

40-1 SOCKET 40-8 SHIM

40-2 VALVE 40-9 ADJUSTING SPRING
40-3 VALVE SEAT 40-10 O-RING IB P7
40-4 CONNECTING PISTON 40-11 BACKUP RING T2P7
40-5 PLUG 40-12 O-RING IB G25
40-6 PILOT SECTION BODY 40-13 BACKUP RING T2G25
40-7 PISTON

Figure 2. Structural drawing of overload valve

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3. Functions

Inflow Outflow Direction of rotation

opening opening (viewed from the shaft side)
VA VB Right (Clockwise)
VB VA Left (Counterclockwise)
Table 1. Direction of rotation

Figure 3. Location of ports

A. Operation of motor
Highly pressurized hydraulic oil delivered from the hydraulic pump enters the inflow orifice located at the brake
valve (42) and is introduced into the cylinder block (3), passing the rear cover (2) and the valve plate (8).
The inflow orifice, outflow orifice and rotational direction of the output shaft are shown in Table 1.

Figure 4 (a) Figure 4 (b)

This highly pressurized hydraulic oil acts on each piston located within the 180° area divided by the Y-Y
border line that draws from the top center and bottom center of the piston, and generates force F1 = P x A
(P: pressure, A: piston’s sectional area).
This force F1 turns into a thrust component force F2 and radial component forces F31 to F34 (or F35) by
shoe plate (11), which has an angle of incline a. (See Fig. 4 (b).) These radial component forces act as a
turning force on Y-Y axis, T = r1•F31 + r2•F32 + r3•F33 + r4•F34, and generate torque.
(If the high pressure acts on the five pistons, r5•F35 should also be added.)
This torque is transferred to the spline on the shaft (9) via cylinder block (3), and then to the shaft (9).

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B. Operation of negative brake

The negative brake is released when hydraulic oil selected as the highest pressure by the counterbalance
valve (42), which is directly connected to the rear cover (2), acts on the brake piston (6). It always
generates brake torque when the pressure is not applied.
This brake torque is generated by frictional force between the separator plate (7), joined via spline with the
casing (1), and the friction plate (5) connected via spline to the cylinder block (3).
When no pressure acts on the brake piston section, the brake piston (6) is pressed by the brake spring (29)
and holds the friction plate (5) and separator plate (7) between itself and the casing (1).
This holding force between the friction plate (5) and the separator plate (7) generates friction force, which
turns into brake torque to lock the cylinder block (3) and the shaft (9).

Figure 5. Negative brake section

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C. Operation of capacity variable mechanism section

Figure 6. Operation of capacity variable mechanism section

The Fig. 6 shows a model of operation of capacity variable mechanism section.
When pressure overwhelming the spring (41-7) enters the high speed travel command line, the spring
(41-7) is compressed and the spool (41-2) moves to the right. As a result, Port P and Port C are connected
and the highest pressure is selected among the following three by the check valve (17): motor pressures A,
B and the high speed travel command line. The highest pressure presses the incline piston (20). For this
reason, the shoe plate (11) inclines with the line (L) between two pivots (22) as an axial center, as shown
by the dotted line, and stops when it contacts the inline stopper (1-1) and maintains the status. As a result,
the volume of inflow and outflow of the piston (14) decreases, which makes the capacity of the motor small
and enables high speed rotation without increasing oil volume sent from the hydraulic pump. In this
machine, the speed turns out to be about 1.7 times as fast as the low speed.
On the contrary, when no pressure exists on the high speed travel command line PA, the spool (41-2) is
returned to the left by the force of the spring (41-7). This will allow the oil, which was pressing the incline
piston (20), to be released into the tank, canceling the pressing force. There are 9 pistons, which are
arranged at equal intervals on the shoe plate (11) and are pushing the shoe plate (11).
The point of application of those forces in total is almost the center of shoe plate (11), as shown in the
figure. Because the position of the poppet (22) is off-centered by S, the rotational force, defined as the
product of the turning force of S and piston’s pushing force, is generated and the original state is
recovered, resuming low speed travel.
In addition, when an operation exceeds the engine’s power (such as climbing up hills at high speeds or
steering in order to prevent the engine from stalling), it automatically switches to low speeds when engine
load exceeds a given value. This mechanism introduces hydraulic pump pressure to Port PB shown in
Fig. 6. This pressure acts on the pin (41-6). When it exceeds a given pressure, the spool (41-2) is returned
to the left by the reaction force of the pin (41-6), and the oil that was pressing the incline piston (20) is
released into the tank. As a result, the shoe plate (11) inclines and increases the capacity of the motor,
which then resumes low speed travel. In addition, when this pressure becomes lower than a given
pressure, the spool (41-2) moves to the right. As a result, high speed travel is resumed.

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D. Operation of overload valve

Two overload valves, which are crossover arrayed, have the following functions:
1. When stopping the hydraulic motor, they keep the braking pressure at a specified value or lower on the
motor delivery side to reduce load inertia.
2. When starting the hydraulic motor, they drive at a given set pressure to accelerate quickly. When stopping,
they limit the generated pressure at a low level for a short time to alleviate the impacts caused by braking.
Also, they alleviate boosting pressure; they keep the circuit pressure at a constant level after smoothing the
engagement of sprockets and others in reduction gears and travel crawlers.
When the pressure on Port A of the overload valve increases at the time of starting the hydraulic motor,
this pressure acts on not only the effective diameter section of the valve (40-2) seated in the valve seat
(40-3), but also on the connecting piston (40-4) inside the valve via a small hole in the valve (40-2) and
boosts to the pressure on Port A. As a result, the valve (40-2) counteracts the adjusting spring (40-9)
with the difference in area between effective diameter section and the connecting piston hole diameter
section and sets the pressure at a given value.
At the time of braking by hydraulic motor, the piston (40-7) located in the rear section is positioned at
the left by the drive pressure. When the pressure at Port A increases, it also acts on the piston (40-7)
via small holes on the valves and moves the piston to the right until it contacts the plug (40-5). At the
same time, the valve (40-2) counteracts the adjusting spring (40-9) and keeps the pressure at Port A
relatively low, releasing the oil into Port B side. After the piston (40-7) touches the plug (40-5), the valve
operates in the same manner as the time of starting the motor.

Figure 7. Operation of overload valve

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TRAVEL UNIT: BRAKE VALVE First Edition: 07/2001

1. Structure

1. MAIN BODY 7. COVER

2. SPOOL 8. THROTTLE VALVE
3. SPRING BEARING 9. SPRING
4. SPRING 10. PLUG
5. O-RING 11. O-RING
6. O-RING 12. HEXAGONAL SOCKET HEAD

Figure 1. Structural drawing

A. Spool
By switching this spool, the shut-off and restriction of delivery oil in the hydraulic motor are automatically
operated to give effects of holding, acceleration, stop, and counterbalance operation to the hydraulic motor.
B. Check valve (integrated into spool)
The valve serves as an oil supply passage to the hydraulic motor and also takes the role of a locking
function for discharged oil. This defines this valve as an inlet valve for the hydraulic motor, as well as a
holding valve.
C. Relief valve (built in hydraulic motor)
When the oil pressure on the supply oil passage or discharge oil passage in the hydraulic motor reaches a
set pressure, it relieves the pressure to the other low pressure side and works as a safety valve in the
circuit.

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TRAVEL UNIT: BRAKE VALVE First Edition: 07/2001

2. Operation
The drawings in this chapter show the flow of oil and movement of movable components under each operating
condition.
A. Holding Status (see Figure 2)
When the switching valve is in the neutral position, Ports VA and VB are connected to the tank and the
spool (2) is held in the center position by the springs at the both ends. Therefore, because the passages
VA to MA and VB to MB are closed, Ports MA and MB connected to both ends of the hydraulic motor are
separately in a contained state.
In addition, as the parking brake passage is connected to the tank, supply pressure on the braking cylinder
in the negative barking mechanism is equal to the pressure in the tank; the brake activates and the rotation
of the hydraulic motor is mechanically prevented.
When external force applies to the hydraulic motor, the motor rotation is usually stopped by the negative
braking. If the negative braking is released, pressure is generated on the Port MA or MB side, but the
highly pressurized oil in the closed circuit escapes due to leakage inside the hydraulic motor. The hydraulic
motor makes a minimal turn. This causes cavitation on the low pressure side in the closed circuit. The
check valve integrated into the spool operates to form a passage VA to MA or VB to MB and to make up for
a volume of oil equivalent to the leakage in the closed circuit to prevent this cavitation.

Figure 2. Holding status

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TRAVEL UNIT: BRAKE VALVE First Edition: 07/2001

B. Accelerating Operation (see Figure 3)

When Port VA is connected with the hydraulic pump and Port VB is connected with the tank by changing
over the switching valve, hydraulic oil from the hydraulic pump, which pushes the check valve in the spool
from Port VA, is supplied to the hydraulic motor through Port MA and attempts to turn the hydraulic motor.
Therefore, the pump’s delivery oil pressure increases, and the brakes in the negative braking mechanism
are released by the pressure supplied by the pump. At the same time, the spool counteracts the spring
force in the pilot chamber at Port VB and moves to the left as the pressure in the pilot chamber increases.
As a result, a return passage, MB to VB, is formed and the hydraulic motor turns.
If the inertia load on the hydraulic motor is excessively large, the pressure required for acceleration
reaches the relief valve’s set pressure, the hydraulic motor gradually increases rotational speed while
relieving the hydraulic oil. As the hydraulic motor increases its rotational speeds, its relief volume
decreases and reaches a constant speed.

Figure 3. Accelerating operation

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TRAVEL UNIT: BRAKE VALVE First Edition: 07/2001

C. Stopping Operation (see Figure 4)

When the delivery oil is cut off by returning the switching valve to the neutral position while the hydraulic
motor is rotating and Ports VA and VB are connected to the tank, both ends of the spool become equal to
the pressure in the pilot chamber and the spool recovers to the neutral position through the force of spring.
Consequently, the passage MB to VB closes. The hydraulic motor still keeps discharging hydraulic oil into
Port MB through pumping action since the hydraulic motor continues to rotate due to inertia force.
However, the passage is shut off, the pressure increases, the relief valve operates, and the hydraulic motor
gradually reduces its speed to stop in the end.
In addition, the released pressure for the negative brake decreases slowly due to the restriction, the brake
eventually turns into the operating status, and the rotation of the hydraulic motor stops.

Figure 4. Stopping operation

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TRAVEL UNIT: BRAKE VALVE First Edition: 07/2001

D. Counterbalance in Operation (see Figure 5)

It is necessary to add counterbalance operation when decelerating the hydraulic motor that is rotating by
force of inertia caused by load.
Suppose that hydraulic oil supplied to Port VB from the hydraulic pump gradually decreases. As the
hydraulic motor attempts to rotate beyond the supplied capacity, the pressure in the pilot chamber on the
Port VB side reduces, the spool is pushed to the left by the spring and moves toward the neutral direction.
Therefore, the pressure on the MA side increases and the hydraulic motor receives braking action because
the passage area of MA to VA decreases and the passage resistance increases.
When the speed is reduced below the rotational speed equivalent to supply oil volume, the pressure in the
pilot chamber on the Port VB side increases, the spool moves to the right and the area of passage MA to
VA increases. As a result, the braking action reduces and the motor rotation speeds are controlled to the
levels that are equivalent to the supply oil volume.
To perform counterbalance operation in a stable manner, restrictions that add damping effects to the spool
are integrated in both ends of the pilot chamber.
Take note that the negative brake is released while the spool is involved in its pressure adjusting action.

Figure 5. When counterbalance is in operation

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PORT LOCATIONS First Edition: 09/2004

1. Hydraulic Pump
Port name Port size
A1, 2 Delivery port SAE6000 psi 3/4"
B1 Suction port SAE2500 psi 2½"
Dr Drain port G 3/4 – 20
PSV Servo assist port G 1/4 – 15
Pi1, i2 Negative control port G 1/4 – 15
a1, 2, 4 Gauge port G 1/4 – 15
A3 Gear pump delivery port G 1/2 – 19
B3 Gear pump suction port G 3/4 – 20

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PORT LOCATIONS First Edition: 09/2004

2. Control Valve
Line name Main port Line name Main port
Bucket-open line B7 Backup confluence line P3, P4
Bucket-close line A7 Return line T1, T2
Boom-down line B8 Negative control signal ps1, ps2
Boom-up line A8 Travel signal pressure measurement PT
Travel forward left line A6 Power Boost PH
Travel backward left line B6 Attachment signal pressure PP, PA
measurement
Arm-out line A5 Drain Dr
Arm-in line B5 Load holding at arm pc1
Swing right line B3 Load holding at boom pc2
Swing left line A3 Bypass filter T4
Backup line A2 Heat circuit T5
Backup line B2 Swing motor makeup T3
Travel forward right line A1 Swing priority pc3
Travel backward right line B1 Swing priority release pbu
Pressure line P1, P2

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PILOT HOSE CONNECTION DIAGRAMS First Edition: 09/2004

1. Pilot P&T Lines

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Pilot P&T Lines

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PILOT HOSE CONNECTION DIAGRAMS First Edition: 09/2004

KBJ10140-E01

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PILOT HOSE CONNECTION DIAGRAMS First Edition: 09/2004

2. Pilot Control Lines

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Pilot Control Lines

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PILOT HOSE CONNECTION DIAGRAMS First Edition: 09/2004

KRJ6122Z-E13

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LIST OF FUNCTIONS First Edition: 09/2004

Operational
Item Description of Functions
Description
Travel Circuits: 290-1-03-03-13
High speed 1. High speeds can be achieved by setting the two-step inclinatory angle of Page 1/6
circuit the travel motor to the smaller angle side.
2. Load pressure applied to the travel motor automatically changes the
speed to a lower one.
3. Travel load pressure does not control the controller.
Low speed Low speeds can be achieved by setting the two-speed inclinatory angle of the Page 3/6
circuit travel motor to the larger angle side.
Straight travel Maintains machine's straight travel even when attachment or swing Page 5/6
circuit operations are performed during its travel.
Swing Circuits: 290-1-03-04-14
Swing parking 1. When the swing lever is in neutral, the swing parking is activated and the Page 1/6
circuit swing is fully held.
2. When the swing lever is operated, the parking brake is released by signals
from the parking switch.
3. When the swing lever is in neutral, the parking brake is released by load
pressure generated by attachment operation.
4. The parking brake starts to operate 5 seconds after the swing lever comes
in neutral and after the load pressure has become lower than the specified
values.
5. When the swing lock switch is turned on, the parking brake starts to
operate.
Swing push When swinging and arm operation are conducted simultaneously, swing Page 5/6
digging pushing function can be obtained by the swing override throttle valve
integrated in the control valve.
Vibration The reverse prevention valve attached to the swing motor reduces —
backlash backlashes that occur when the swing stops.
Arm Circuits:290-1-03-06-13
Arm-out circuit Switching over arm (1) and (2) spools makes hydraulic oil flows merge, Page 1/6
achieving faster speed.
Arm-in load 1. Load holding valve integrated in the control valve reduces natural drop on Page 3/6
holding valve the arm-in side.
circuit 2. Arm-in pilot pressure enables arm-in operation by releasing the load
holding valve.
Arm-in circuit The regenerative circuit and forced regenerative release valve in the arm (1) Page 5/6
spool function achieves faster arm speed.

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LIST OF FUNCTIONS First Edition: 09/2004

Operational
Item Description of Functions
Description
Boom Circuits: 290-1-03-07-13
Boom-up circuit 1. Switching over boom (1) and (2) spools makes hydraulic oil flows merge, Page 1/8
achieving faster speed.
2. When the arm is operated with the boom simultaneously, the restriction is
opened in the swing override variable restriction valve and the flow volume
to the arm side is secured.
Boom-down load 1. Load holding valve integrated in the control valve reduces natural drop of Page 5/8
holding the boom.
2. Boom-down pilot pressure enables boom-down operation by releasing the
load holding valve.
Boom-down 1. The regenerative circuit in the boom (1) spool serves to improve the Page 7/8
circuit boom's speed and prevent negative pressure from occurring.
2. Boom (2) does not operate.
3. The bleed-off circuit in the spool reduces extra vibrations when the boom
is lowered.
Backup Circuits: 290-1-03-09-11
Combined circuit 1. Backup circuit section is provided at control valve. Page 1/4
2. Changing over the spool in the control valve creates internal confluence.
Other
Cushion 1. A cushion valve with heat circuit is attached to the pilot line to reduce —
shocks when the arm or boom movement stops.
2. There is no soft/hard switch.
Auto power Through the engine load ratio and circuit pressure, the pressure of the main —
boost relief will be raised from 34.3 MPa to 37.3 MPa.
Negative control This is designed to reduce power consumption by minimizing the flow of the —
discharge from the hydraulic pump when operating with no load.

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TRAVEL CIRCUITS First Edition: 09/2004

1. High Speed Travel Circuit

With High Speed Travel, high speeds can be achieved by setting the two-level inclinatory angle of the travel
motor to the smaller angle side. The circuit has a travel motor that automatically switches over to lower speed
by utilizing load pressure on the travel motor when traveling at high speed.
Discharged oil from the hydraulic pump A1 enters the Port P1 of control valve while discharged oil from the
hydraulic pump A2 enters the Port P2 of control valve. Each flow goes into the travel motor by switching
between the right and left travel spools. By these flows, the machine travels forward and backward.
By operating the travel mode switch, electric signals are sent to the controller, and from the controller, electric
signals are sent to the solenoid valve for 2-speed (high speed) travel in the 4-way solenoid valve. By the
switchover of the solenoid valve, the original pilot pressure (3.9 MPa) from Port C1 on the 4-way solenoid
valve enters Port P of right and left travel motors via the center joint to set the inclinatory angle of the travel
motor to the smaller angle side, which enables high speeds.

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High Speed Travel Circuit

Hydraulic Circuits Page No. 2/ 6

TRAVEL CIRCUITS First Edition: 09/2004

BOOM CYLINDER

T2 T1

A8
P P B8

VB VA
VA VB
B6
A6 pb6
pa6
B1 STRAIGHT TRAVEL VALVE
TRAVEL MOTOR
A1
pb1
pa1

P1 PP P2
SWITCH PANEL

TRAVEL

PRESSURE LINE 2-SPEED TRAVEL LEVER LOCK

PILOT PRESSURE LINE C1

A1 A2 A3
CONTROLLER
DRAIN LINE P
TANK LINE

PILOT TANK LINE

ELECTRIC LINE
4-WAY SOLENOID VALVE

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TRAVEL CIRCUITS First Edition: 09/2004

2. Low Speed Travel Circuit

The two-level inclinatory angle in the travel motor is set to the larger angle side. When the travel status is set
to high speed and the key switch is turned off and turned on again, the speed setting will always return to Low
Speed.
Discharged oil from the hydraulic pump A1 enters the Port P1 of control valve while discharged oil from the
hydraulic pump A2 enters the Port P2 of control valve. Each flow goes into the travel motor by switching
between the right and left travel spools. By these flows, the machine travels forward and backward.
The solenoid valve for high speed travel is turned off and the oil in Port P of the travel motor enters the tank
line and establishes a connection. As a result, the inclinatory angle of the travel motor is set to the larger angle
side.

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Low Speed Travel Circuit

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TRAVEL CIRCUITS First Edition: 09/2004

BOOM CYLINDER

T2 T1

A8
P P B8

VB VA

VA VB B6
A6
pb6
pa6
B1 STRAIGHT TRAVEL VALVE
TRAVEL MOTOR
A1
pb1
pa1

P1 PP P2
SWITCH PANEL

TRAVEL

PRESSURE LINE 2-SPEED TRAVEL LEVER LOCK

T
PILOT PRESSURE LINE C1
A1 A2 A3
CONTROLLER
DRAIN LINE P
TANK LINE

PILOT TANK LINE

ELECTRIC LINE
4-WAY SOLENOID VALVE

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TRAVEL CIRCUITS First Edition: 09/2004

3. Straight Travel Circuit

As an example, we describe the operation where travel and boom up are operated at the same time.
The pilot oil pressure enters from Port PP of the control valve and communicates with the tank side via
passages of travel spool and spools for attachments (boom, arm, bucket and swing). When travel and
boom-up operations are performed simultaneously, all circuits, which have been communicating with the tank,
will be shut off by spools. This disables the pilot pressure oil that enters from Port PP to locate its destination,
and the original pressure (3.9 MPa) acts on the pilot chamber of the straight travel valve. As a result, the
straight travel valve switches over.
As the result of the switchover of the straight travel valve, the pressurized oil in the control valve P1 drives the
right and left travel motors and the pressurized oil in the control valve P2 drives the attachments. The right and
left pressures become equal because one pump drives both the right and left motors. This realizes straight
travel. Additionally, extra hydraulic oil from P2 is supplied via the check with travel confluence restriction to the
travel side, and speed reduction is minimized. The same theory applies and the circuits operate the same way
when upper actuators other than boom and travel are operated at the same time.

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Straight Travel Circuit

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TRAVEL CIRCUITS First Edition: 09/2004

BOOM CYLINDER

Dr T2 T1

A8
P P B8
pb8

pb4 pa8

VB VA

VA VB
B6
A6
pb6
pa6
B1 STRAIGHT TRAVEL VALVE
TRAVEL MOTOR
A1
pb1
pa1

SWITCH PANEL P1 PP P2

TRAVEL

LEVER LOCK
PRESSURE LINE 2-SPEED TRAVEL
T

PILOT PRESSURE LINE C1

A1 A2 A3
CONTROLLER
DRAIN LINE P

TANK LINE

PILOT TANK LINE

ELECTRIC LINE
4-WAY SOLENOID VALVE

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SWING CIRCUITS First Edition: 09/2004

1. Swing Parking Circuit (Lever in Neutral / Swing Locked)

When the engine is started and the swing lever is in neutral, the swing brake solenoid valve becomes turned
on (24 V input) and the swing parking brake is activated.
When the swing lock switch is on, even if the swing pressure switch or attachment pressure switch is turned
on, the swing lock switch overrides and the parking brake remains unreleased. When the swing lock switch is
on and the swing lever is shifted into operation, the swing spool in the main control valve will be switched over.

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Swing Parking Circuit (Lever in Neutral / Swing Locked)

Hydraulic Circuits Page No. 2/ 6

SWING CIRCUITS First Edition: 09/2004

SWING MOTOR

PRESSURE LINE

PILOT PRESSURE LINE

A5
DRAIN LINE B5

TANK LINE ARM CYLINDER

PILOT TANK LINE

pc3
ELECTRIC LINE

A B
B3
A3

pa3

REMOTE CONTROL VALVE

2S 3S
SHUTTLE
VALVE
S2 S3 S1
3 1
SWING PRESSURE
P1 PT PP PA P2
SWITCH
PRESSURE SENSOR
T ATTACHMENT
LEVER LOCK PRESSURE SWITCH

G4 G5
SWITCH PANEL SWING LOCK
SWING BRAKE A1 A2 A3
C2

4-WAY SOLENOID VALVE

CONTROLLER

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SWING CIRCUITS First Edition: 09/2004

2. Swing Parking Circuit (with Brake Released)

When the swing pressure switch is turned on by operating the lever, output to the swing brake solenoid valve
from the controller is turned off and the swing parking brake is released by pilot pressure. Also, in order to
prevent brake dragging caused by swing lateral force that is generated when digging attachments are moved
with the swing lever being in neutral, a mechanism which senses main pressure and releases the parking
brake is introduced. Signals from the pressure sensor on Port G4 or Port G5 of the hydraulic pump enter the
controller. When either pressure reaches 15 MPa, the output to swing brake solenoid valve from the controller
is turned off. This releases the swing parking brake.
When the pressure switch for attachments is kept off for more than 5 seconds, the swing pressure switch will
be turned off. Then 5 seconds after the pressure of the hydraulic pumps G4 and/or G5 becomes 15 MPa or
less, the solenoid valve turns on and the swing parking brake starts operating. When the pressure on G4 and/
or G5 becomes 15 MPa or more, the swing brake is released. However, if the attachment switch was kept off
for more than 5 seconds, the swing parking brake works. (When traveling)

Swing Pressure received on

Swing brake solenoid Swing motor
Key switch pressure G4 or G5 pressure
valve parking brake
switch sensor
OFF OFF 0 OFF Operates
15 MPa or less ON Operates
OFF Released
OFF
15 MPa or more Turns on 5 seconds after
ON attachment pressure Operates
switch is turned OFF.
15 MPa or less OFF Released
ON
15 MPa or more OFF Released

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Swing Parking Circuit (with Brake Released)

Hydraulic Circuits Page No. 4/ 6

SWING CIRCUITS First Edition: 09/2004

SWING MOTOR

PRESSURE LINE
ARM CYLINDER T2
PILOT PRESSURE LINE
A5
DRAIN LINE B5

TANK LINE

PILOT TANK LINE

pc3
ELECTRIC LINE pbu

A B
B3
A3
pb3
pa3

REMOTE CONTROL VALVE

2S 3S
SHUTTLE
VALVE
S2 S3 S1
3 1
SWING PRESSURE
P1 PT PP PA P2
SWITCH
PRESSURE SENSOR
T ATTACHMENT
LEVER LOCK PRESSURE SWITCH

G4 G5
P SWITCH PANEL SWING LOCK
SWING BRAKE A1 A2 A3
C2

4-WAY SOLENOID VALVE

CONTROLLER

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SWING CIRCUITS First Edition: 09/2004

3. Swing Push Digging

The swing pilot pressure is supplied to Port Pc3 via the shuttle valve and enables the swing priority variable
restriction to be held to the right-hand side. Putting restriction on the parallel circuit secures swing force for
enforced digging operation with raised swing pressure even when the arm and swing are operated at the
same time.

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Swing Push Digging

Hydraulic Circuits Page No. 6/ 6

SWING CIRCUITS First Edition: 09/2004

SWING MOTOR

PRESSURE LINE
ARM CYLINDER T2
PILOT PRESSURE LINE
A5
DRAIN LINE B5
pb5 pb9
TANK LINE pa5 pa9
PILOT TANK LINE
pc3
ELECTRIC LINE

A B
B3
A3
pb3
pa3

REMOTE CONTROL VALVE

2S 3S
SHUTTLE
VALVE
S2 S3 S1
3 1
SWING PRESSURE
P1 PT PP PA P2
SWITCH
PRESSURE SENSOR
T ATTACHMENT
LEVER LOCK PRESSURE SWITCH

G4 G5
P SWITCH PANEL SWING LOCK
SWING BRAKE A1 A2 A3
C2

4-WAY SOLENOID VALVE

CONTROLLER

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ARM CIRCUITS First Edition: 09/2004

1. Arm-Out Circuit
Oil discharged from hydraulic pump A1 is supplied to the arm (1) spool through the center bypass oil passage
in the control valve. Oil discharged from hydraulic pump A2 is also supplied to the arm (2) spool through the
parallel oil passage, and merges at the upstream of the arm (1) spool, then flows into the rod side of the arm
cylinder via the load holding valve. Oil returning from the bottom returns to the tank oil passage via the arm (1)
and (2) spools.

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Arm-Out Circuit

Hydraulic Circuits Page No. 2/ 6

ARM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
T2 T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
pbu pb8
pa8
pb4
A

B
CUSHION VALVE

P1 PP P2

REMOTE CONTROL VAVLE G H D C

PRESSURE LINE

PILOT PRESSURE LINE A1 A2 A3

DRAIN LINE
2 4
TANK LINE

PILOT TANK LINE

B A
ELECTRIC LINE T
CUSHION VAVLE

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ARM CIRCUITS First Edition: 09/2004

2. Arm-In Load Holding

When the arm is in neutral, oil on the arm cylinder rod side is sealed by the load holding valve check. This
mechanism reduces internal leakage from the main spool.
When the arm-in is operated, the pilot pressure enters Port Pb5 of the control valve and moves arm (1) spool
to the arm-in side. Also, the pilot pressure separated from Port Pb5 enters Port Pc1 and moves the load
holding valve spool to the right. Through this mechanism, the oil in the spring chamber of the load holding
valve check is connected to the tank line passing the load holding valve spool. As a result, the pressure on the
spring chamber decreases and the load holding valve check is released. The hydraulic oil in the rod of the arm
cylinder is returned to the tank line, the arm cylinder extends and the arm moves in.

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Arm-In Load Holding

Hydraulic Circuits Page No. 4/ 6

ARM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
Dr T2 T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
Detail pb8
pbu
LOAD HOLDING pa8
VALVE SPOOL pb4

pc1 A

LOAD HOLDING
A5
VALVE CHECK
B
CUSHION VALVE
ARM(1)

P1 PP P2

REMOTE CONTROL VAVLE G H D C

PRESSURE LINE

PILOT PRESSURE LINE A1 A2 A3

DRAIN LINE
2 4
TANK LINE

PILOT TANK LINE

B A
ELECTRIC LINE T
CUSHION VAVLE

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ARM CIRCUITS First Edition: 09/2004

3. Arm-In Circuit
For arm-in operation, pilot pressure is supplied to Port Pb5 and Port Pb9 of the control valve and the arm
spool moves to the arm-in side.
At the same time, the arm load holding valve is released by the pilot pressure, and the discharged oil on the
cylinder rod side is restricted by the forced regenerative release valve. This forces the returned oil to be
regenerated into the cylinder bottom side via the check within arm (1) spool, securing the arm speeds
required for floor digging work. When the load pressure rises on the cylinder bottom side, the forced
regenerative release valve switches over to the large diameter restriction side. As a result, the orifice for return
becomes large and returned oil on the rod side stops recycling.
When the reverse notching operation is performed for skeleton work (arm-out → quick arm-in), the arm (2)
spool line closes even though the pressure oil supplied to the cylinder remains the same as the volume of two
pumps, and only the arm (1) spool return line stays open. This causes extensive shock. To reduce this shock,
a cushion valve (inline) is provided in the arm (2) spool OUT pilot line which softens the switchover of the
spool.

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Hydraulic Circuits Page No. 6/ 6

ARM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
Dr T2 T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
Detail pbu pb8
pa8
pb4
A5
H/V LOAD HOLDING VALVE CHECK
A
B5

pb5 B CUSHION VALVE

FORCED RECYCLE
RELEASE VALVE

P1 PP P2

REMOTE CONTROL VAVLE G H D C

PRESSURE LINE

PILOT PRESSURE LINE A1 A2 A3

DRAIN LINE
2 4
TANK LINE

PILOT TANK LINE

B A
ELECTRIC LINE T
CUSHION VAVLE

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BOOM CIRCUITS First Edition: 09/2004

1. Boom-Up Circuit (Single)

Oil discharged from hydraulic pump A1 is supplied to the boom (2) spool from the parallel oil passage via the
control valve and merges at the downstream of the boom (1) spool. Oil discharged from hydraulic pump A2
merges with the discharged oil from the boom (2) via the boom (1) spool through the parallel oil passage and
flows into the bottom side of the boom cylinder via the holding valve.

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BOOM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
Dr T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
pbu pb8
pa8
pb4

CUSHION VALVE

P1 PP P2

REMOTE CONTROL VAVLE G H C

PRESSURE LINE

PILOT PRESSURE LINE A1 A2 A3

DRAIN LINE
2 4
TANK LINE

PILOT TANK LINE

E F
ELECTRIC LINE T
CUSHION VAVLE

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BOOM CIRCUITS First Edition: 09/2004

2. Boom-Up Circuit (Combined)

When floor digging operation is performed, the boom-up pilot pressure, which is supplied to Port Pbu,
releases the restriction on flow to the arm by moving the swing priority variable restriction to the left. This
makes the arm move smoothly.

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BOOM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
T2 T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
pbu pb8
pa8
pb4

B CUSHION VALVE

P1 PP P2

REMOTE CONTROL VAVLE G H D C

PRESSURE LINE

PILOT PRESSURE LINE A1 A2 A3

DRAIN LINE
2 4
TANK LINE

PILOT TANK LINE

E F A
ELECTRIC LINE T
CUSHION VAVLE

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BOOM CIRCUITS First Edition: 09/2004

3. Boom-Down Load Holding

When the boom is in neutral, oil on the boom cylinder bottom side is sealed by the load holding valve check.
This mechanism reduces internal leakage from the main spool. For boom-down operation, the pilot pressure
enters Port Pb8 of the control valve and moves the spool of the control valve to the boom-down side. Also, the
pilot pressure enters Port Pc2 and moves the load holding valve spool to the left. Through this mechanism, the
oil in the spring chamber of the load holding valve check passes the load holding valve spool creating a
connection to the tank. Consequently, the pressure on the spring chamber decreases and the load holding
valve check is released. The hydraulic oil at the bottom side of the boom cylinder is returned to the tank line,
the rod of the boom cylinder shrinks, and the boom is lowered.

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BOOM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
Dr T1
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
pbu pb8
pa8
pb4

CUSHION VALVE

Datail
LOAD HOLDING
VALVE SPOOL
pc2

LOAD HOLDING
VALVE CHECK A8

P1 PP P2 BOOM(2)
BOOM(1)

REMOTE CONTROL VAVLE G H C PRESSURE LINE

A1 A2 A3 PILOT PRESSURE LINE

DRAIN LINE

2 4 TANK LINE

PILOT TANK LINE

E F ELECTRIC LINE
T
CUSHION VAVLE

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BOOM CIRCUITS First Edition: 09/2004

4. Boom-Down Circuit
For boom-down operation, pilot pressure is supplied at Port Pb8 of the control valve, and the boom spool
moves to the boom-down side. At the same time, the pilot pressure opens the boom load holding valve and
partially regenerates the discharged oil from the bottom side of boom cylinder at the rod side via the check in
the spool. (The lower the load pressure of the cylinder rod side, the more the regenerated volume will be.)
When the boom is moved down as quickly as possible and the spool is at full stroke, negative pressure is
generated by bleed-off oil passage in the center bypass. High pressure generation is controlled, and vibration
of the body is reduced. Since the lack of oil is to be supplemented in the regenerative circuit, engine output
can be effectively used.

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BOOM CIRCUITS First Edition: 09/2004

BOOM CYLINDER
Dr T1 ps2
pc1
A5
B5
pb5 pb9
ARM CYLINDER pa9
pa5
pc2
A8
pc3 B8
pbu pb8
pa8
pb4

CUSHION VALVE

Datail LOAD HOLDING

VALVE CHECK
H/V A8

B8

pb8

P1 PP P2
T1

P2 BLEED-OFF

REMOTE CONTROL VAVLE G H C PRESSURE LINE

A1 A2 A3 PILOT PRESSURE LINE

DRAIN LINE

2 4 TANK LINE

PILOT TANK LINE

E F ELECTRIC LINE
T
CUSHION VAVLE

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BACKUP CIRCUITS First Edition: 09/2004

1. Combined Circuit (Breaker Circuit)

Through remote control operation, the pilot pressure that is supplied to Port Pa2 of the control valve switches
the backup spool. This allows the discharged oil from the hydraulic pump A1 to flow into the breaker.
The pilot pressure operates the pressure switch at the same time. Through signals, the control gives an
instruction to the engine controller to adjust the number of engine revolutions to preset numbers.
The returned oil from the breaker returns to the hydraulic oil tank via the 3-directional valve. If there is oil that
has a higher pressure value than its set pressure, it returns to the hydraulic oil tank via the relief valve through
the stop valve.

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BACKUP CIRCUITS First Edition: 09/2004

SHUTTLE VALVE
DIRECTION
VALVE

STOP VALVE

pb5 pb9
FILTER pa9
pa5

B2
pb2 A2
pa2
P4
D

1 T 2
P

PRESSURE A
P2 P3
P1 PP
SWITCH A1 S1 A2
P T
B HOLDEING VALVE
SHUTTLE
VALVE
B1 S2 B2 A

PRESSURE LINE

PILOT PRESSURE LINE

A1 A2 A3
CONTROLLER DRAIN LINE

TANK LINE

PILOT TANK LINE

ELECTRIC LINE

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BACKUP CIRCUITS First Edition: 09/2004

2. Combined Circuit (High Speed Confluence Circuit)

Through remote control operation, the pilot pressure that is supplied to Port Pa2 (or Pb2) of the control valve
switches the backup spool. This allows the discharged oil from the hydraulic pump A1 to flow into the end
attachment.
The pilot pressure operates the pressure switch at the same time, and its signals switch over the solenoid
valve. Through the switchover of the solenoid valve, the pilot pressure, which is supplied to Port Pb9 of the
control valve, switches the arm (2) spool to block the center bypass. Through this process, discharged oil from
the hydraulic pump A2 is supplied to holding valve B via Ports P2 and P3 of the control valve.
The pilot pressure from the solenoid valve acts on Port P of the holding valve at the same time and moves the
release spool. As a result, the oil in Port B of the holding valve is discharged from Port A and enters Port P4
on the control valve and merges with the discharged oil from the hydraulic pump A1 at the upstream of the
backup spool, achieving 2nd speed (high speed).

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BACKUP CIRCUITS First Edition: 09/2004

SHUTTLE VALVE
DIRECTION
VALVE

T2
STOP VALVE

pb5 pb9
FILTER pa9
pa5

B2
pb2 A2
pa2

T P4
D

1 T 2
P

PRESSURE A
P2 P3
P1 PP
SWITCH A1 S1 A2
P T
B HOLDEING VALVE
SHUTTLE
VALVE
B1 S2 B2 A

PRESSURE LINE

PILOT PRESSURE LINE

A1 A2 A3
CONTROLLER DRAIN LINE

TANK LINE

PILOT TANK LINE

ELECTRIC LINE

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

1. System Chart of Functions

Engine Control (2) Electronic Governor Control

ITEM FUNCTION METHOD

a. H/S/L modes
Machine settings can be selected Maximum number of engine revolutions,
according to priorities such as workload, pump current and boosting solenoid
Operation Mode Selection (3) fuel or the operation mode, such as valves are regulated, depending on the
slinging. selected operation mode.

b. Auto-mode When Auto-mode is selected, load is

Operation mode is automatically selected calculated from pressure of negative
depending on the job to be performed. control, P1 and P2. The result determines
the operation mode to be used.

Operator can adjust the revolutions to The number of engine revolutions is

Throttle Control (4) any level from idling to high-idle. adjusted by throttle volume.

Operator can switch between idling Pressing the right knob switch will switch
control by an easy one-touch ON/OFF engine to idling; pressing the switch again
switch. will set the engine to regain the prior
revolutions.
Idling Control (5)
When Auto Idle is selected, the engine
When the machine is not in operation, revolutions automatically go down to
engine revolution can be automatically idling five minutes after putting the lever
reduced to idling. in neutral. Operating the lever results in
regaining the prior engine revolutions.

When pressure switch is set in the

breaker pilot line and it is turned ON, a
Pressing the breaker pedal automatically pre-set revolution rate is obtained. (This
Breaker Mode (6) sets the flow rate suited for breaker as requires setting breaker revolution rate in
well as cuts the boosting pressure. advance.) Also, pump current will be set
as S-mode current and the boosting
pressure will be cut off.

Depending on the temperature of the

coolant at the time the key is switched on,
Helps engine to start more easily in the glow plug comes on for a
colder temperatures. Also stabilizes the programmed time frame, heating the
Auto Preheat (7) initial engine revolutions on start-up, thus combustion chamber. The glow plug can
reducing smoke. also be programmed to stay on for a
certain time frame following engine start-
up to reduce black smoke exhaust.

If the coolant temperature is low after

start-up and the machine stays unused, it
Automatically starts warming up engine if gradually raises the engine revolutions to
Auto Warm-up (8)
it is cold at start-up. warm up the engine as well as distributing
lubricant to the entire engine.

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

ITEM FUNCTION METHOD

Raises the idling revolutions by up to

Prevents over-cooling/battery discharge
200 min-1 more than normal when the
Idling Up (9) when the coolant temperature/battery
coolant temperature/power voltage to
voltage is low.
engine control is low.

The emergency stop switch, when

Stops the engine when there is a problem pressed, regulates the normal engine
Engine Emergency Stop (10) and the engine will not stop through stop. It also activates the stop motor to
turning the key switch OFF. stop fuel flow.

Regulates fuel injection flow through

Prevents engine from shutting off when signals from engine revolution sensor and
Limp-home Control (11) rack sensor in engine governor breaks drives the engine temporarily during limp-
down. home controlling.

For entering/leaving the cab or when the

Operating the gate lever on the console
machine needs to stay still, this acts as a
Lever Lock (12) turns lever lock solenoid ON / OFF. When
lock to prevent the machine from running
it is OFF, pilot pressure is cut and the
even when maneuvered by the control
machine does not run.
lever.

Boost Control
Depending on the input data on engine
Automatically increases relief pressure by load and pump discharge pressure, it
Auto Boost Control (13) approximately 10% when more power is boosts the pressure for 8 seconds when
needed for digging. necessary.
Boost-cut Control
Cuts boosting to protect machine when a Forcefully cuts boosting when travel
component that does not withstand pressure switch and optional line
boosted pressure is in operation. pressure switch is ON.

When the swing lock switch is turned on,

Disables swing movement even when the
Swing Lock (14) the swing brake solenoid turns on,
machine is mistakenly maneuvered by
activating the mechanical brake that is
the swing lever.
built into the swing break.

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

ITEM FUNCTION METHOD

When swing lock is OFF, the swing Based on the data on swing,
mechanical brake automatically turns attachments, travel pressure switch, and
Swing Brake Control (15) ON/OFF according to the operational pump discharge pressure P1 and P2, it
condition. This protects the machine by determines the ON/OFF status of swing
preventing the swing motor/reduction mechanical brake and regulates the
gear from becoming overloaded. swing brake solenoid valve.

When high-speed (2-speed) travel mode

is selected by the travel mode switch in
There are two travel speeds to switch
the monitor, the solenoid valve turns on
Travel Speed Switch-Over (16) between according to work site
and the pressure goes into the PS port of
conditions and the intended operation.
the travel motor. As a result, the incline of
the motor switches to high-speed side.

Alerts crew/people in surrounding area Buzzer comes on when travel pressure

Travel Alarm (17)
about machine movement. switch is turned on.

Shuts the power off once the engine Ensures delay time before battery relay
Delayed Power Shut-off (18) stops and stabilizes. turns off once the key switch is turned off.

The area to detect over-current is

Protects controller when a short-circuit designated in the controller. This serves
Power Transistor occurs at the power transistor output to stop the power transistor output in
Protection Circuit (19) destination. case of a short-circuit at output
destination.

a. Normal Display The hydraulic oil temperature, coolant

temperature, fuel level are displayed in
Displays the current status of the bar graphs on the full-dot LCD on the
Monitor Display (20) machine. monitor. Current operation/travel modes
and ON/OFF status of auto-idle are also
displayed.
b. Message Display
Warning messages Provides text information along with bar
Messages indicating certain functions graph display on LCD.
Messages indicating service intervals

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

2. Engine Control
Description of basic engine control operation (electronic governor control)

1. Fuel injection control

a. The engine controller computes the target number of revolutions based on the following: operation
mode data sent via CAN communication from the controller, input signal (voltage) from the throttle
volume, signal (voltage) from the coolant temperature sensor and the voltage signal supplied to the
engine controller.
b. The engine controller then computes the difference between this target number of revolutions and
the actual number of revolutions (obtained from TDC rotational sensor and backup sensor). The
controller uses the result to calculate the fuel flow.
c. The engine controller converts the fuel flow value into target rack position and corrects the target
rack position according to the Q-adjusting resistance. (The rack is located inside the governor, and
the movement of the rack controls and adjusts the fuel injection level.)
d. The engine controller converts the computed target rack position. It then outputs it to the electronic
governor.
e. The electronic governor performs computation based on target rack position output from engine
controller and the governor’s built-in rack signal representing the actual rack position. The governor then
outputs the result and moves the DC motor to regulate the rack position (i.e. regulates the fuel flow).

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

2. Engine control at start-up

a. Positioning the starter switch to cranking position will turn ON the starter motor. The cranking signal
is also sent to the engine controller (ON = iGN).
b. When the cranking signal turns on, the engine controller determines the fuel injection level through
start-up control. The fuel flow is determined according to the coolant temperature and the actual
number of engine revolutions.
c. Once the cranking signal turns off, the engine controller shifts from the start-up fuel control to normal
injection level control.
3. Engine control at shut-off
a. Upon recognizing the engine shut-off signal (either Key Switch OFF or Emergency Stop Switch ON),
the engine controller transmits a signal to the governor to indicate the rack position for no injection.
The controller also switches ON (= GND) the pull-down signal.
b. The pull-down signal is directly transmitted into the governor. When this signal turns on, the
governor automatically moves the rack to the no-injection position.
c. Normally the pull-down signal initiates the engine shut-off. In the event that the pull-down signal
connection is not working properly, the rack is still positioned at the no-injection position by the
no-injection signal.
4. Governor servo error and limp-home
a. The signal from the governor’s built-in rack sensor goes into the engine controller as well as being
input directly to the governor.
b. The engine controller compares the target position that is signaled out to the governor and the
actual rack position that is signaled from the rack sensor. The controller determines from this result if
the rack is positioned properly.
c. If the engine controller determines that the rack is not positioned where targeted, it recognizes this
as governor servo error and stops the engine.
d. If the limp-home switch is ON (= GND) during governor servo error, the engine will run in limp-home
mode (the engine will not start when the limp-home switch is off).
Since this model is designed to have the limp-home switch connected to GND (ON) constantly, the
engine will automatically start in limp-home mode when it is restarted following a governor servo
error. This happens even when the key switch is not turned off after the engine shut-off.
e. In limp-home mode, rack position is determined solely by the engine rpm sent from the engine
rotational sensor. The actual position of the rack does not control the rack target position.

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

3. Operation Mode Selection

1. Circuit configuration

2. Time chart

3. Switching modes
If the machine was in H/S/L mode and was turned off by the key switch, it will restart in S-Mode
when it is turned on through the key switch again. (The previous data is reset.)
By pressing the operation mode switch, the modes alternate as follows: S H L S H.
No matter what mode is selected to start with, pushing the auto-mode switch once will switch the
mode to “auto”. Pushing the switch again will switch the auto-mode to S-mode, regardless of the
mode that was selected prior to auto-mode.
During the auto-mode operation, the operation mode switch stays deactivated. The switch will not
work to change modes.
After the machine has been turned off with auto-mode selected, it will restart in the auto-mode even
when the key switch is turned on. (Previous data is retained.)
4. Operation
a. Pushing the mode switch on the monitor display will send a signal to the controller. The controller
then switches modes according to the signal it received.
b. The controller signals the currently selected mode to the monitor via serial communication. The LCD
screen switches according to the data sent.
c. The controller transmits the current mode to the engine controller via CAN communication. The
engine controller regulates the engine governor according to the data.
Also, the engine controller transmits via CAN communication the data on current mode and the
actual number of engine revolutions.

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

d. The controller determines the pump current based on the following data: current mode, actual
number of engine revolutions, target number of engine revolutions. The controller then transmits the
result to the pump.
e. The LCD on the monitor switches, reflecting the transmission received from controller via serial
communication.
5. Switches and LCD

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

A. Controls in H/S/L modes

1. Circuit configuration

2. Overview
H-mode: Engine revolutions = MAX (min-1)
Pump controlling current = Variable current (Imax to Imin)
Type of boost = Auto boost control
S-mode: Engine revolutions = MAX – 200 (min-1)
Pump controlling current = Fixed current (90% torque)
Type of boost = Auto boost control
L-mode: Engine revolutions = MAX – 300 (min-1)
Pump controlling current = Fixed current (70% torque)
Type of boost = Constant boost
3. Configured setting for each mode
Mode Item Unit SH290-3
H-Mode Engine revolutions (MAX) min–1 2,250 ± 10
Current mA (I MAX) mA 415
(I MIN) mA 305
When not in operation mA <50
–1
S-Mode Engine revolutions (MAX) min 2,050 ± 10
Current mA (STD) mA 305
When not in operation mA <50
L-Mode Engine revolutions (MAX) min–1 1,950 ± 10
Current mA mA <50
During Engine revolutions
idling min–1 1,000

Engine revolutions during auto idle min–1 1,200

–1
Engine revolutions at maximum torque min 1,800

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

4. Supplementation
Configured settings in the previous page are meant for normal operations. The following applies on
irregular occasions. (Details are explained in each section.)
a. When the target number of engine revolutions falls below the maximum number of torque
revolutions, the pump current value will be the L-mode current value even when the machine is in
the H-mode or S-mode.
b. When the machine is traveling in the L-mode and is not performing any task other than travel, the
S-mode current value is adopted. (To prevent overrunning of engine.)
c. During L-mode operation, the pump current value will be the value of the L-mode current. However,
when a backup line (breaker, crusher, etc.) is being used, the S-mode current value is adopted.
d. When the engine coolant temperature is low, or when power supply voltage to the engine controller
is low, the number of idling revolutions is increased to prevent overcooling or battery discharging.
e. Exceptions to b.) and c.) exist in which case the L-mode current value will be adopted. This is when
the conditions resemble the situation that is described in a.).

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DESCRIPTION OF FUNCTIONS First Edition: 09/2004

B. Controlling auto-mode
1. Circuit configuration

2. Overview
a. During auto-mode, the modes switch between SA and LA, depending on the operational condition as
shown in the following table.
b. When auto-mode is selected, the machine initially starts in LA-mode. Afterwards it will switch to
SA-mode as needed, depending on the operational condition.The mode also switches from SA to LA
automatically as needed.
c. Even in auto-mode, the automatic control will not be in effect if the coolant temperature is below
50°C or oil temperature is below 25°C. In this case, LA-mode at start-up will be the fixed mode.
However, once coolant temperature reaches 50°C or above and oil temperature reaches 25°C or
above, auto-mode resumes control. The mode continues to be in effect even if coolant temperature
and oil temperature drop again.
d. When the travel pressure switch turns ON during the auto-mode control, the operation mode will not
change as long as the travel pressure switch is on. (If the switch turns on during SA-mode, the
machine will remain in SA-mode. If the switch turns on during LA-mode, it will remain in LA-mode.)

Mode Item Unit SH290-3

–1
SA-Mode Engine revolutions (MAX) min 2,050 ± 10
Current mA 345
mA
(=S+60)
Type of boost — Auto-boost
–1
LA-Mode Engine revolutions (MAX) min 1,950 ± 10
Current mA (STD) mA 305 (=S)
When not in operation mA <50
Type of boost — Auto-boost

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4. Throttle Control
1. Circuit configuration

2. Operation
a. The controller transmits the currently selected operation mode to the engine controller via CAN
communication.
b. The engine controller calculates the target number of revolutions based on the following: the engine
output selected according to the operation mode and the analog signal (voltage) of throttle volume
transmitted to engine controller.
c. The engine controller calculates the target rack position based on the computed value of target
revolutions and data from each sensor (actual number of engine revolutions, actual position of rack,
Q-adjusting resistance). The engine controller then transmits the signal to the electronic governor.
d. The electronic governor performs calculation based on the target position of rack and the actual
position of rack (the reading of governor’s built-in rack sensor). The governor then activates the DC
motor and moves the rack to adjust the fuel injection level.
e. The engine controller repeats the processes above and regulates the electronic governor until the
adjustment is complete and the actual number of revolutions equals the target number of
revolutions.
f. If the number of engine revolutions was forced below the maximum torque number of revolutions
through throttle volume, the current value of the pump will be the current value of L-mode,
regardless of the operation mode selected (S-mode or H-mode).
Throttle volume versus engine revolutions

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5. Idling Control (Auto/One-touch)

1. Circuit configuration

2. Switching between auto idle and one-touch idle

a. Pushing the knob switch (IN1) down and holding it for 3 seconds will trigger the modes to toggle
between auto and one-touch.
When the mode switches, the ON/OFF display on the auto idle section of the LCD also switches,
and the buzzer buzzes for 3 seconds.
b. At the time of auto idle/one-touch idle selection, the previous setting will still prevail even after the
key switch was turned ON. (Previous data is retained.)
c. The LCD will display ON/OFF status of auto idle. ON on the display indicates the auto idle, OFF
indicates one-touch idle.
d. If there occurs no handling through the lever for 5 seconds with auto idle turned ON (both
attachment pressure switch and travel pressure switches are OFF), the number of engine
revolutions automatically goes back to the idling state.
(For 5 seconds, the initial setting prevails. Programming is possible through adjusting settings on the
back panel for the duration between 1 and 30 seconds.)
e. During auto idle, if operated via lever while engine is idling (either attachment pressure switch or
travel pressure switch is on), the number of engine revolutions automatically goes back to the
previous rate.
f. Even during auto idle, idling/recovery operation is attained by pressing the knob switch (one-touch
switch).
g. When auto idle is OFF (i.e. during one-touch idle), idling/recovery is attained by simply operating the
knob switch (one-touch idle switch), whether or not the machine was maneuvered though the lever.
h. LCD displays IDLING on the monitor during idling control.
3. Operation
a. When setting idling revolutions based on conditions described in 2. Switching between auto idle and
one-touch idle, the controller transmits an idling signal to the engine controller via CAN
communication.
Also, a signal is sent to the monitor display via serial communication to display IDLING on the
screen.
b. The engine controller, upon receiving the signal, selects idling mode and adjusts engine revolutions
to that of the idling state.
c. The monitor displays IDLING on the LCD according to the signal sent.
d. When recovering from idle control based on the conditions described in 1. Circuit configuration, the
controller transmits a signal to the engine controller via CAN communication conveying the previous
engine mode selection.

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Also, the serial transmission that has been sent to the monitor for displaying IDLING on the screen
will be terminated.
e. The engine controller, depending on the mode signal received, switches the idling mode back to the
previous mode and adjusts the engine revolutions.
f. The monitor recognizes the termination of the idling signal transmission and stops the IDLING
display on LCD.
4. Time chart
a. Time chart for auto idle ON/OFF selection

b. Time chart when auto idle is ON

c. Time chart when auto idle is OFF

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6. Breaker Mode
1. Overview
With Type 2 models, the number of breaker revolutions is regulated when the breaker pressure switch
turns on. With Type 3, however, the control takes place when the input is ON as well as the backup line
pressure switch turns on.
2. Circuit configuration

3. Operation
a. If the controller’s breaker mode switch is ON, the controller executes its controls in breaker mode.
(When input is OFF, the controller regulates in crusher mode.)
b. When the backup line pressure switch turns ON while operating in breaker mode, the controller
transmits the breaker mode to the engine controller via CAN communication.
c. When the engine controller receives the transmitted breaker mode, it adjusts the engine revolutions
so it equals the number of breaker setting revolutions. (For details on setting the breaker revolutions,
refer to the service and support functions.)
d. If backup line pressure switch turns ON while the number of engine revolutions is below the number
of breaker setting revolutions, no change occurs in the number of engine revolutions.
(In breaker mode, an adjustment takes place to lower the revolutions, but no adjustment will
be done to increase it.)
e. While the backup line pressure switch is ON, the pump current value will be the same as the S-mode
current value, regardless of the operation mode at the time.
4. Time chart

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7. Auto Preheat
1. Circuit configuration

2. Operation
a. When the key switch is turned ON (IN1 = ON), the engine controller computes the pre-glow time
according to the engine coolant temperature (Tp). It computes according to the map shown on the
next page.
b. The engine controller turns on the glow relay output during the computed pre-glow time frame (Tp).
It also transmits the preheat signal to the controller via CAN communication.
c. When pre-glow is complete, the engine controller terminates transmission of preheat signal to the
controller. However, it continues transmission to the glow relay for another 2 seconds.
d. When the key switch is turned to START (IN2 = ON), the engine controller turns on the glow relay
output once more. However, it does not transmit the preheat signal to the controller.
e. The engine controller computes the after glow time (Ta) according to the engine coolant
temperature, noted on to the map shown on the next page.
f. After the key switch is turned from the START to the ON position (IN1 = ON, IN2 = OFF), the engine
controller turns on the glow relay output during the after glow time frame (Ta). However, it does not
transmit the preheat signal to the controller.
g. The controller transmits the Engine preheat signal to LCD on display monitor while the preheat
signal via CAN communication continues from engine controller.
h. Because the control mentioned above starts immediately after key switch is turned on, the engine
preheat message will not be displayed on the monitor unless the pre-glow time takes longer than
3 seconds (coolant temperature lower than -5 °C).
(This allows the display of the PAX logo as the initial screen for 3 seconds after key switch is turned on)

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3. Pre-glow time (Tp) and after glow time (Ta) maps

4. Flow chart
Auto warm-up (engine glow) flow

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5. Time chart
a. If cranked within 2 seconds after engine pre-glow display (normal conditions)

b. When cranked 2 seconds after completion of engine preheat display

c. When cranked during engine preheat display

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8. Auto Warm-up
1. Circuit configuration

2. Operation
a. A coolant temperature sensor is installed inside the engine. The signal from this sensor goes out to
the engine controller and is converted into a temperature value. The engine controller then transmits
the coolant temperature data to the controller via CAN communication.
b. If the coolant temperature is below 50 °C after engine starts, the controller transmits the auto warm-
up signal to the engine controller via CAN communication.
c. The engine controller executes the auto warm-up control upon receiving the signal transmission
from the controller.
d. The controller terminates the auto warm-up control on the following conditions.
The engine controller terminates the auto warm-up control once the command is cancelled.
• When one of the following switches turns on: 1) attachment pressure switch, 2) travel pressure
switch, 3) knob switch (one-touch idle switch).
• When throttle volume is changed.
• When engine revolution stays above 1,800 min-1 for 3 minutes.
e. Once auto warm-up control is cancelled, the controller does not initiate auto warm-up control again
unless key switch is turned from OFF to ON.
f. While controller is executing the auto warm-up control, an auto warm-up message is displayed on
the monitor’s LCD.
3. Auto warm-up control
Details of auto warm-up control are the same as those for model 2 machines. They are as follows:

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9. Idling Up
The idling up function is designed to prevent the battery from discharging or to prevent the coolant
temperature from dropping when the machine has been left idling for an extended period of time. This is
achieved by automatically raising the idling revolutions when the power voltage to the engine controller drops
or when the engine coolant temperature drops.
1. Circuit configuration

2. Operation
The idling revolutions for adjusting battery voltage is determined according to the power voltage
supplied to the engine controller. The map shown below is used as a reference to obtain the revolutions.
The idling revolutions value for adjusting coolant temperature is determined based on the coolant
temperature value that was converted from the transmitted input (voltage) from the coolant temperature
sensor. The following map is also used as a reference to determine the final value.
Of the two output values: a) idling revolutions output for adjusting battery voltage b) idling revolutions
output for adjusting coolant temperature, the one that is greater is the idling revolutions value.
3. Characteristics of idling revolutions for voltage adjustment and characteristics of idling
revolutions for coolant temperature adjustment

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10.Engine Emergency Stop

1. Circuit configuration

2. Operation
a. Pressing the emergency stop switch on the display initiates the monitor’s transistor output
(OUT1 = 0 V). The LED on the switch also turns on.
b. As a result of OUT1 voltage dropping to zero, the stop motor relay becomes energized, causing
the engine stop motor to rotate to the stop position.
c. The engine controller’s engine stop signal input (IN1) falls to 0 V. The engine controller then
recognizes this as an emergency stop and activates the transistor output (OUT2 = 0 V) of the pull-
down signal.
d. The engine governor, upon receiving the pull-down signal, initiates control for stopping the engine.
(rack position = 0 mm)
e. The emergency stop status holds against trials via key switch (off to on). (The previous data will be
retained.)
3. Time chart

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11.Limp-home Control
1. Overview of governor servo error control
The electronic governor engine controls the engine revolutions by regulating the rack position inside the
governor.
• The engine controller outputs the rack’s target position to governor via PWM signal. With this
target position and the rack’s actual position attained from governor’s built-in rack sensor circuit,
the governor performs calculation. It then uses the result and activates the DC motor to regulate
the position of the rack. The data on rack’s actual position attained from rack sensor is also
transmitted to engine controller.
• The engine controller compares the rack’s target position that is sent out to governor and the
rack’s actual position that is sent from governor. The controller uses the result of this comparison
to verify if the governor is positioned properly.
• In the event that the difference of 2 mm or greater has been detected between the actual position
and the target position of the rack over the duration specified below, the engine controller
recognizes this as governor servo error.
• In case of a governor servo error, the engine controller shuts off the engine to prevent it from
overrunning.
• During governor servo error, the engine controller transmits the failure mode to controller via
CAN communication. When it receives the failure mode, the controller transmits it to monitor
display via serial communication for the Faulty Electrical System warning to be displayed on
monitor’s LC screen.
Duration when the engine controller reaches the decision that there has been a governor servo
error

When starter switch is ON When starter switch is OFF

(cranking) (during operation)
When engine revolutions stays equal to or When engine revolutions stays equal to or
greater than 500 min-1: greater than 1000 min-1:
1 sec 1 sec

When engine revolutions stays below 500 min-1: When engine revolutions stays below 100 min-1:
10 sec 10 sec

2. Limp-home control
a. Overview of limp-home control
1) When engine controller determines that there has been a governor servo error while the engine
is running or while cranking, it shuts off the fuel injection to stop the engine.
2) If the engine is restarted with limp-home switch ON (IN3 = ON = GND) after it has been shut off
due to governor servo error, it will restart in limp-home mode.
(The machines are wired so the limp-home switch is on at all times, meaning that the engine
automatically restarts in limp-home mode after there has been an engine shut-off due to
governor servo error.)
3) When the machine has been running and an engine shut-off occurs, it will start in limp-home
mode when cranked again. If the starter switch is turned off once, however, crank to intentionally
cause a governor servo error again. Stop cranking and crank once more, and then the machine
will restart in limp-home mode.
4) During limp-home control, rack positioning is regulated solely through the engine rebolutions that
is attained from engine rotational sensor. Consequently, the regular performance of the engine is
not to be expected during this control. The engine will be regulated as though it was an
emergency situation.

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b. Circuit configuration

c. Time chart

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d. Engine control during limp-home

• The engine controller determines the target engine revolutions by converting the transmitted
voltage of the throttle volume.
• The engine controller computes the difference between the actual engine revolutions signaled
from governor’s built-in rotational sensor (or backup sensor installed inside flywheel housing) and
the target engine revolutions. The controller then regulates the rack according to the result of this
computation.
• During limp-home mode, engine revolutions is regulated solely by throttle volume. (Settings for
maximum engine revolutions for operation modes selected will not be reflected during this
control.)
Also the control by throttle volume will not be the same as the control during normal operation. It is
shown in the following diagram.

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12.Lever Lock
1. Circuit configuration

2. Time chart

3. Operation
a. By positioning the gate lever on cab console (left) toward operation (gate lever sticks out when this is
done) while the machine is powered on, the limit switch will be turned ON (closed) and the lever lock
solenoid valve will be ON.
b. When the lever lock solenoid valve is ON, pressure can reach the pilot line, enabling the machine to
operate.
c. By positioning the gate lever toward entering/leaving cab (gate lever stays housed), the limit switch
will be turned OFF (open) and the lever lock solenoid valve turns OFF.
d. When the lever lock solenoid valve turns off, pressure cannot reach the pilot line. Thus the operation
of the machine will be disabled.

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13.Auto Boost Control

1. Auto boost control during each operation mode
SH290-3
H-Mode Auto boost (*1)
(Pressure setting) (34.3/37.3MPa)
S-Mode
(*1)
(Pressure setting)
L-Mode
Constant boost (*1)
(Pressure setting)
*Note:Boosting is cut when travel pressure switch or backup line pressure switch is on.

2. Auto boost control

a. Circuit configuration

b. Overview of auto boost control

During H/S modes, the controller calculates the operational load from the engine load data
transmitted from engine controller via CAN communication and the main pressure P1/P2 data
obtained from pressure sensor installed in the main pump. If necessary, the controller turns on the
boost solenoid valve to boost the main pressure.
The duration of the boost is limited to 8 seconds to prevent the boost from lasting too long.
The output to boost solenoid valve will immediately be terminated to stop boosting when the travel
pressure switch or the backup line pressure switch turns on. This is to protect the actuators (travel
motor, crusher, etc.) which cannot run during boost.

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14.Swing Lock

15.Swing Brake Control

1. Circuit configuration

2. Operation of swing lock

a. Overview
Pressing the swing lock switch on monitor display will turn on the red LED, activating the swing
lock control. Pressing the swing lock switch again will turn off the LED, and the swing lock is
deactivated.
During swing lock control, controller’s transistor output turns on and the mechanical brake that is
built in the swing motor turns on.
The ON/OFF state of the swing lock holds when turning the key switch from OFF to ON.

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b. Time chart

c. Swing brake auto control

1) Overview
The auto control of the swing brake takes place when the swing lock is OFF.
The auto control also releases the mechanical brake automatically during a digging operation as
well as during swing operation. If the operation is halted, the auto control turns on the mechanical
brake automatically.
The detailed conditioning for ON/OFF of the swing mechanical brake is shown below.
• The swing brake will be turned OFF based on the following conditions.
a) Pressure switch (swing) is ON
b) P1>15 MPa or P2>15 MPa
• The swing brake will be turned ON based on the following conditions.
a) Pressure switch (attachment) stays OFF for 5 seconds
b) Key switch is OFF
• The swing mechanical brake will be deactivated once when the pump delivery pressure
(P1 or P2) grows over 15 MPa during travel. However, it will take effect in 5 seconds.

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16.Travel Speed Switch-over

Low-speed travel function will be deactivated.

SH290-3
II High speed Inclines toward high-speed of the travel motor
(switches automatically)
I Low speed Inclines toward low-speed of the travel motor

1. Circuit configuration

2. Time chart

3. Switching travel modes

a. Regardless of the mode the machine was in when the key switch was off, the mode will always be
Travel I (low speed) when the switch is turned on. (The previous data will be reset.)
b. By pressing the travel mode switch, signal (IN1: 0 V) will be sent out to the controller, and the modes
will toggle between I and II (low and high).
c. The controller transmits to the monitor the necessary updates to be displayed.
d. The monitor display receives transmission and reflects the updated content on LCD.

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4. Operation
a. When Travel I (low speed) is selected
• The controller output (OUT) and the 2-speed travel switch-over solenoid valve stay OFF at all
times. Also the travel motor will always incline toward low-speed.
b. When Travel II (high speed) is selected
Even when the controller’s output is on, if the travel motor’s drive pressure is high, the mode will be
switched over to low-speed through the function of the motor itself (auto 2-speed function).

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17.Travel Alarm
1. Circuit configuration

2. Time chart
The pressure switch (travel) will be turned ON through the travel lever operation. The travel alarm will
sound for 10 seconds, then stop.

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18.Delayed Power Shut-off

1. Circuit configuration

2. Time chart

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19.Power Transistor Protection

Controller

In the event that a solenoid valve or a relay develops a short circuit, the power transistor output will be shut off
in order to protect the controller. A faulty electrical system message will be displayed during the failure.
Perform the service support check to have the location of failure pinpointed and displayed.
Then follow the display result and inspect the wire or the equipment that seems to be experiencing the failure.

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20.Monitor Display

1. Radiator coolant temperature

a. Circuit configuration

b. Operation
1) Coolant temperature sensor is installed inside the engine. The signal from this sensor (Vtw) will
be transmitted to engine controller as an analog signal (voltage).
2) The engine controller convert5ant temperature data to the controller via CAN communication.
3) When the controller receives the signal, it uses to the graph shown above to determine the bar
graph display level for the signal level. The controller then transmits the data to monitor display
via serial communication.
4) When the monitor display receives transmission, it reflects the data received as a bar graph on
the display.
5) OVERHEAT will be displayed when level 8 lights up on the scale. (The engine does not stop.)

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2. Hydraulic oil temperature

a. Circuit configuration

b. Operation
1) Hydraulic oil temperature sensor is installed inside the suction piping. The signal from this sensor
(Vto) will be transmitted to controller as an analog signal (voltage).
2) When the controller receives the signal, it first converts it into a temperature value. The controller
then uses to the graph shown above to determine the bar graph display level for the signal level.
The controller then transmits the data to monitor display via serial communication.
3) When the monitor display receives transmission, it reflects the data received as a bar graph on
the display.
4) OVERHEAT will be displayed when level 8 lights up on the scale.

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3. Fuel level
a. Circuit configuration

Remaining fuel (L) Fuel sensor Input voltage

Bar graph
SH290-3 resistance (Ω) Vfl (V)

>261.6 10.0 to 18.1 0.455 to 0.766 8

232.8 to 261.6 18.1 to 23.9 0.766 to 0.964 7
190.0 to 232.8 23.9 to 29.6 0.964 to 1.142 6
147.1 to190.0 29.6 to 36.5 1.142 to 1.337 5
104.2 to147.1 36.5 to 46.3 1.337 to 1.582 4
51.2 to 104.2 46.3 to 60.8 1.582 to 1.891 3
25.6 to 51.5 60.8 to 74.7 1.891 to 2.138 2
<25.6 74.7 to 80.0 2.138 to 2.222 1 (Refill fuel)

b. Operation
1) Fuel sensor is installed inside the fuel tank. The signal from this sensor (Vfl) will be transmitted to
the controller as an analog signal (voltage).
2) When the controller receives the signal, it uses to the graph shown above to determine the bar
graph display level for the signal level. The controller then transmits the data to monitor display
via serial communication.
3) When the monitor display receives transmission, it reflects the data received as a bar graph on
the display.

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Warning displays (messages)

Buzzer Messages displayed Descriptions/Measures

Engine preheat During engine preheat (glow).
Auto warm-up During engine auto warm-up. Auto warm-up will be
cancelled by either moving throttle volume or lever.
Idling While the engine is at low idle.
Powered-up digging When digging is powered up.
Service machine Reminders are displayed at each 500-hour interval. Each
display stays on for 1 min (Total of 5 displays) Refer to
service intervals chart and service the machine.
Sounds Refill fuel The fuel level is very low. Fill tank with fuel.
Sounds Refill coolant The coolant level is too low. Refill coolant.
Sounds Engine oil pressure The engine oil pressure has dropped abnormally low. Shut
off engine and check engine oil level. Refill if necessary.
Sounds Overheat Engine coolant temperature or hydraulic oil temperature is
abnormally high. Turn engine down to low-idle to lower the
temperature. Check radiator and oil cooler.
Sounds Battery charge Fault in battery charging system. Check electric circuit.
Sounds Faulty electrical system Fault in electric system (short circuit or disconnected wire).
Check electric circuits.

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1. Overview
1. Current machine status display
Displays the current operating status.
2. Error diagnosis display
Displays current error code, previous error codes, and the time errors took place.
3. Task history display
Displays each task and its duration.
4. Resetting options display
Displays current settings on which to base resetting values to better suit the user’s preference.

2. Operating Instructions

Operating switches
A: Switches when travel/operation mode switch stays ON more than 3 seconds.
B: Switches when auto-mode switch turns ON.
C: Switches when buzzer stop switch turns ON.
D: Data will be cleared when operation mode switch stays ON more than 10 seconds. (Buzzer
sounds when data is cleared.)
E: The function to be reset becomes selectable with the buzzer stop switch ON. Resetting can be
done when travel mode switch turns ON, and resetting of data occurs when operation mode
switch stays on more than 10 seconds. (Buzzer sounds as data is being reset.)

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F: When the travel mode switch turns ON, output check is performed if protection circuit is
operating.
G: If the travel mode switch stays ON more than 10 seconds, the short-circuit auto detection results
will be displayed. (Buzzer comes on also.)
1. Status display (CHK 1)
CHK MODE II. H ENG 2 0 0 0 rpm MODE: Travel mode, Operation mode
1 P1: Main pump (P1) pressure
P1 0 3 0. 0 MPa I 0 3 0 0 mA P2: Main pump (P2) pressure
N: Negative control (N1) pressure
P2 0 3 0. 0 MPa WT 0 0 8 0 °C ENG: Engine revolutions
I: Pump control current values
N 0 3. 0 0 MPa OT 0 0 5 5 °C
WT: Radiator fluid temperature
OT: Hydraulic oil temperature

Procedure of changing indicated unit

1) Indicate CHK 1 screen according to Operating Instructions the above.
2) The indicated unit is changed as followings when Working Lamp switch is pressed during CHK
screen is indicating.
Pressure; Kgf/cm2 (Initial) ... >MPa

DIAG MODE II. H ENG 2000 rpm DIAG MODE II. H ENG 2000 rpm
1 1
P1 0 3 0. 0 MPa I 0300 mA P1 0306 K I 0300 mA

P2 0 3 0. 0 MPa WT 0080 °C P2 0306 K WT 0080 °C

N 0 3 0. 0 MPa OT 0055 °C N 0306 K OT 0055 °C

3) These changed units, pressure and temperature are shown even key switch is turned OFF
because these are memorized at that time.
2. Status display (CHK 2)
CHK MODE II. H TR1 0000 R: Engine load ratio ((Q-Qn) / (Qf-Qn))
2 FT: Fuel temperature
R 0080 % TR2 0000 TV: Throttle volume opening
TR1: Controller transistor output
FT 0 0 4 0 °C TR3 0000 TR2: Controller transistor output
TR3: Controller transistor output
TV 0100 % TR4 0000
TR4: Controller transistor output

Controller transistor output (0=OFF, 1=ON)

TR1 0000 TR2 0000 TR3 0000 TR4 0000
Swing brake Battery relay ********* *********
2-speed travel ******** Anti-theft protection *********
Travel alarm ********* ********* *********
Boosting ********* ********* *********

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3. Status display (CHK 3)

CHK MODE II. H SW4 0000 SW1: Controller switch input (Sensor switch)
3 SW2: Controller switch input (Sensor switch)
SW1 0000 SW5 0000 SW3: Controller switch input (Sensor switch)
SW4: Controller switch input (operational switch)
SW2 0000 SW6 0000 SW5: Controller switch input (operational switch)
SW6: Controller switch input (operational switch)
SW3 0000 SW7 0000
SW7: Controller switch input (operational switch)

Controller switch input; Sensor switch (0=OFF, 1=ON)

SW1 0000 SW2 0000 SW3 0000
Attachment pressure switch Engine pressure switch Battery charge
Travel pressure switch Coolant switch *********
Swing pressure switch ********* *********
Breaker pressure switch ********* *********

Controller switch input; operational switch (0=OFF, 1=ON)

SW4 0101 SW5 0000 SW6 0000 SW7 0000
********* Swing lock Windshield washer Anti-theft protection
********* Emergency stop ********* Key switch
********* Working light Breaker mode *********
One-touch idle Wiper L/M Mode *********

4. Status display (CHK 4)

CHK MODE I. H TG 0000 FS: Fuel sensor resistance
4 AC: Temperature information for air conditioning
FS 0080 Ω BP 0000 TR 5: NPN transistor output
TG: Target revolutions (min-1)
AC 0004 SP1 0000 BP: Boom bottom pressure (MPa)
SP1: *********
TR5 0010 SP2 0000
SP2: *********

AC 0004 TR5 0 0 0 0
1: WT<30°C *********
2: 30°C≤WT<45°C *********
3: 45°C≤WT<65°C *********
4: 65°C≤WT<75°C *********

5. Status display (CHK 5)

CHK MODE II. H TR1 0101 R: Engine load ratio ((Q-Qn) / (Qf-Qn))
5 FT: Fuel temperature
R 0080 % TR2 0001 TV: Throttle volume opening
TR1: Transistor output when overcurrent is detected.
FT 0 0 4 0 °C TR3 0000 TR2: Transistor output when overcurrent is detected
TR3: Transistor output when overcurrent is detected
TV 0100 % TR4 0000
TR4: Transistor output when overcurrent is detected

a. Indicates output status when overcurrent was detected in the past on the CHK 2 display while the
travel mode switch is on.
b. Data is cleared by resetting the error code on the diagnosis display.
c. The example shown above indicates that the travel alarm, swing brake and battery relay were
outputting when overcurrent was detected.

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6. Status Indication (CHK 6)

CHK MODE II. H TR1 0010 R: Engine load ratio ((Q-Qn) / (Qf-Qn))
6 FT: Fuel temperature
R 0080 % TR2 0000 TV: Throttle volume opening
TR1: Short circuit auto detect results
FT 0 0 4 0 °C TR3 0000 TR2: Short circuit auto detect results
TR3: Short circuit auto detect results
TV 0100 % TR4 0000
TR4: Short circuit auto detect results

a. If the key switch is turned ON while also turning ON the one-touch idle switch, the auto detection for
short circuit starts to operate. (Do not start the engine here.)
b. If the travel mode switch stays on more than 10 seconds after switching to the CHK 2 display, the
auto detection results will be displayed.
c. The illustration above indicates that the 2-speed travel line is currently short-circuited.
d. The data is cleared when the key switch is turned off.
7. Fault diagnosis (DIAG 1), current fault status of engine system (Error codes)
DIAG MODE II. H E 0000 E: Engine system error codes
1
E 0015 E 0000

E 0000 E 0000

E 0000 E 0000 Example: Water sensor fault

Error codes
E 0014: Turbo boost pressure sensor
(This sensor is not used on our machine, please disregard this code.)
E 0015: Water (antifreeze) thermosensor
E 0016: Fuel thermosensor
E 0025: Fuel folw adjuster resistance (Q-resistance)
E 0031: Internal circuit of governor, linear servo motor
E 0032: Rack sensor
E 0033: ECU system
E 0041: Engine speed (TDC/RPM) sensor
E 0042: Back-up (Engine speed) sensor

E 0000: No faults

8. Fault diagnosis (DIAG 2), Previous fault status of engine system (Error codes)
DIAG MODE II. H E 0000 E: Engine system error codes
2
E 0032 E 0000

E 0016 E 0000

E 0000 E 0000 Example: Rack sensor fault, fuel temperature sensor

fault

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9. Fault diagnosis (DIAG 3), Previous fault status of engine system (Time of occurrence for
errors)
(Controller hour meter value)
DIAG MODE II. H E 0000 E: Engine system error codes
3
E 1200 E 0000

E 1000 E 0000
Examples: Rack sensor fault: Error occurred at 1200 HR
E 0000 E 0000 Fuel temperature sensor fault: Error
occurred at 1000 HR

a. The previous error codes and the time of occurrence will be cleared when the operation mode switch
[9] stays on more than 10 seconds.
b. The time displayed is the time when the error occurred for the first time after data had been cleared.
(Time will not be recorded after the second occurrence.)
c. When data is cleared, the data relating to [6] and [7] are saved in EEPROM. (There will be no output
to the monitor. For data retrieval through PCs only.)
10. Fault diagnosis (DIAG 4), Current fault status of machine’s main body (Error codes)
DIAG MODE II. H M 0000 M: Error codes for machine’s main body
4
M 0020 M 0000

M 0000 M 0000

M 0000 M 0000
Example: Oil temperature sensor fault

Error codes
M 0010: Transistor output short-circuit M 0080: Pressure switch (attachments or travel)
M 0020: Oil temperature sensor M 0090: CAN communication error
M 0030: Fuel sensor M 00A0: Controller reset
M 0040: Pressure sensor (P1) M 00B0: Engine controller mismatch
M 0050: Pressure sensor (P2) M 00C0: **********
M 0060: Pressure sensor (N2) M 00D0: **********
M 0070: Key switch M 00E0: **********

M 0000: No faults

11. Fault diagnosis (DIAG 5), Previous fault status of machine’s main body (Error codes)
DIAG MODE II. H M 0000 M: Error codes for machine’s main body
5
M 0020 M 0000

M 0030 M 0000 Example: Oil temperature sensor fault, fuel sensor fault

M 0000 M 0000

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12. Fault diagnosis (DIAG 6), Previous fault status of machine’s main body (Error codes)
DIAG MODE II. H M 0000 M: Error codes for machine’s main body
6
M 1200 M 0000
Examples: Oil temperature sensor fault: Error occurred
M 1000 M 0000 at 1200 HR
Fuel sensor fault: Error occurred at 1000 HR
M 0000 M 0000

a. The previous fault codes and the time of occurrence will be cleared when the operation mode switch
stays on more than 10 seconds.
b. The time displayed in [12] is the time when the error occurred for the first time after data had been
cleared. (Time will not be recorded after the second occurrence.)
c. When data is cleared, the data relating [11] and [12] are saved in EEPROM. (There will be no output
to the monitor. For data retrieval through PCs only.)
13. Task history (HR 1)
HR MODE II. H T 0000 HR ENG: Hour meter (Duration of power generation by
1 alternator)
ENG 0000 HR S 0000 HR WRK: Duration of machine operation (attachments
ON or travel ON)
WRK 0000 HR PU 0000 HR U: Duration of attachment operation
T: Duration of travel operation
U 0000 HR BRK 0000 HR S: Duration of swing operation
PU: Duration of boost
BRK: Duration of breaker operation

14. Task history (HR 2)

HR MODE II. H A 0 0 0 0 HR H: Duration of H-mode operation
2 S: Duration of S-mode operation
H 0 0 0 0 HR WT 0 0 0 0 °C L: Duration of L-mode operation
A: Duration of A-mode operation
S 0 0 0 0 HR OT 0 0 0 0 °C WT: Maximum coolant temperature
OT: Maximum oil temperature
L 0 0 0 0 HR FT 0 0 0 0 °C
FT: Maximum fuel temperature

15. Task history (HR 3)

HR MODE II. H 4 0000 1: Duration controller stayed ON
3 2: Duration of I-mode operation
1 0000 5 0000 3: Duration of II-mode operation
4: Duration of Travel without performing tasks
2 0000 6 0000 5: Service intervals (on export models,
resetting can be done through buzzer stop
3 0000 7 0000 switch)
6: **********
7: **********

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16. Task history (HR 4)

Distribution of P1 pressure
HR MODE II. H 4 0000
4 1: Total duration of P1 at 10 MPa or below
1 0000 5 0000 2: Total duration of P1 between 10 MPa and 15 MPa
3: Total duration of P1 between 15 MPa and 20 MPa
2 0000 6 0000 4: Total duration of P1 between 20 MPa and 25 MPa
5: Total duration of P1 between 25 MPa and 30 MPa
3 0000 7 0000
6: Total duration of P1 between 30 MPa and 35 MPa
7: Total duration of P1 at 35 MPa or more

17. Task history (HR 5)

Distribution of P2 pressure
HR MODE II. H 4 0000
5 1: Total duration of P2 at 10 MPa or below
1 0000 5 0000 2: Total duration of P2 between 10 MPa and 15 MPa
3: Total duration of P2 between 15 MPa and 20 MPa
2 0000 6 0000 4: Total duration of P2 between 20 MPa and 25 MPa
5: Total duration of P2 between 25 MPa and 30 MPa
3 0000 7 0000 6: Total duration of P2 between 30 MPa and 35 MPa
7: Total duration of P2 at 35 MPa or over

18. Task history (HR 6)

Distribution of engine revolution
HR MODE II. H 4 0000
6 1: Total duration of N at 1175 min-1 or below
1 0000 5 0000 2: Total duration of N between 1175 min-1 and 1375 min-1
3: Total duration of N between 1375 min-1 and 1575 min-1
2 0000 6 0000 4: Total duration of N between 1575 min-1 and 1775 min-1
5: Total duration of N between 1775 min-1 and 1975 min-1
3 0000 7 0000 6 Total duration of N between 1975 min-1 and 2175 min-1
7 Duration of N between 2175 min-1 or over

19. Task history (HR 7)

Distribution of coolant temperature
HR MODE II. H 4 0000
1: TW: Total duration that temperature is 77°C or
7 below (1, 2 increments on bar graph scales)
1 0000 5 0000 2: TW: Total duration that temperature is between
77°C and 82°C (3 increments on bar graph scales)
2 0000 6 0000 3: TW: Total duration that temperature is between
82°C and 97°C (4 increments on bar graph scales)
3 0000 7 0000 4: TW: Total duration that temperature is between 97°C
and 100°C (5 increments on bar graph scales)
5: TW: Total duration that temperature is between 100°C
and 103°C (6 increments on bar graph scales)
6: TW: Total duration that temperature is between
103°C and105°C (7 increments on bar graph scales)
7: TW: Total duration that temperature is 105°C or
above (8 increments on bar graph scales)

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20. Task history (HR 8)

Oil temperature distribution
HR MODE II. H 4 0000
8 1: TO: Total duration that temperature is 45°C or
1 0000 5 0000 below (1, 2 increments on bar graph scales)
2: TO: Total duration that temperature is between
45°C and 60°C (3 increments on bar graph scales)
2 0000 6 0000
3: TO: Total duration that temperature is between
60°C and 80°C (4 increments on bar graph scales)
3 0000 7 0000 4: TO: Total duration that temperature is between
80°C and 88°C (5 increments on bar graph scales)
5: TO: Total duration that temperature is between
88°C and 95°C (6 increments on bar graph scales)
6: TO: Total duration that temperature is between
95°C and 98°C (7 increments on bar graph scales)
7: TO: Total duration that temperature is 98°C or
above (8 increments on bar graph scales)

21. Task history (HR 9)

Fuel temperature distribution
HR MODE II. H 4 0000
9 1: TF: Total duration that temperature is 30°C or
1 0000 5 0000 below
2: TF: Total duration that temperature is between
30°C and 40°C
2 0000 6 0000
3: TF: Total duration that temperature is between
40°C and 50°C
3 0000 7 0000 4: TF: Total duration that temperature is between
50°C and 60°C
5: TF: Total duration that temperature is between
60°C and 70°C
6: TF: Total duration that temperature is between
between 70°C and 80°C
7: TF: Total duration that temperature is 80°C or
above

22. Task history (HR 10)

Load ratio distribution:
HR MODE II. H 4 0000
10 R = (Q - Qn) / (Qf - Qn)
1 0000 5 0000 1: R: Total duration that ratio is 30% or less
2: R: Total duration that ratio is between 30% and 40%
2 0000 6 0000
3: R: Total duration that ratio is between 40% and 50%
4: R: Total duration that ratio is between 50% and 60%
3 0000 7 0000
5: R: Total duration that ratio is between 60% and 70%
6: R: Total duration that ratio is between 70% and 80%
7: R: Total duration that ratio is 80% or above

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23. Task history (HR 11)

HR MODE II. H 4 0000
Load ratio distribution during high idle H-Mode
11 R = (Q - Qn) / (Qf - Qn)
1 0000 5 0000 1: R: Total duration that ratio is 30% or below
2: R: Total duration that ratio is between 30% and 40%
2 0000 6 0000
3: R: Total duration that ratio is between 40% and 50%
4: R: Total duration that ratio is between 50% and 60%
3 0000 7 0000
5: R: Total duration that ratio is between 60% and 70%
6: R: Total duration that ratio is between 70% and 80%
7: R: Total duration that ratio is 80% or above

24. Task history (HR 12)

Load ratio distribution during high idle S-Mode
HR MODE II. H 4 0000
12 R = (Q - Qn) / (Qf - Qn)
1 0000 5 0000 1: R: Ratio 30% or below
2: R: Total duration that ratio is between 30% and 40%
2 0000 6 0000 3: R: Total duration that ratio is between 40% and 50%
4: R: Total duration that ratio is between 50% and 60%
3 0000 7 0000 5: R: Total duration that ratio is between 60% and 70%
6: R: Total duration that ratio is between 70% and 80%
7: R: Total duration that ratio is 80% or above

When the operation mode switch remains on for more than 10 seconds on any of the modes from [11]
through [24], all task history data will be cleared.

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25. Reset (RST 1)

RST MODE II. H PA 0000 MODE: Travel mode, Operation mode
1 BRK: Engine revolutions setting for breaker
BRK 0000 rpm AU 0000 L/M: Engine revolutions setting for LIFTING MAGNET
AI: Auto idle time setting (1 to 30 seconds)
L/M 0000 rpm HLD 0000 PA: Pump output adjustment (0 = off, 1 = on)
AU: Auto boost (0 = boost, 1 = none)
AI 0000 sec OUT 0000 HLD: Setting with previous data retained
OUT: Setting for PC communications (0 = waiting for
transfer, 1 = transferring)

HLD 0000
Auto mode (0 = Previous data retained, 1 = Previous data reset)
Operation mode (0 = Previous data reset, 1 = Previous data retained)
Travel mode (0 = Previous data reset, 1 = Previous data retained)
*******

Reset example 1: Setting breaker revolutions

a. Select the breaker revolutions using buzzer stop switch.
(The selected item changes from negative display to positive display.)

RST MODE II. H PA 0000

1
BRK 1800 rpm AU 0000

L/M 0000 rpm HLD 0000

AI 0000 sec OUT 0000

b. Then, set the breaker revolutions at 1800 rpm. Start the engine and adjust the engine revolutions
with throttle volume while observing the monitor. When adjustment is complete, leave the operation
mode switch ON for 10 seconds. Buzzer sounds when data storing is complete.
c. Turn OFF the key switch. (Do so with the engine revolution set as above.)

Reset example 2: Changing Auto idle time

a. Select the auto idle time using buzzer stop switch. (The selected item changes from negative display
to positive display.)

RST MODE II. H PA 0000

1
BRK 1800 rpm AU 0000

L/M 0000 rpm HLD 0000

0000 Sec OUT 0000

b. Set the Auto idle time at 10 seconds. Using travel mode switch, set the number at 10. Every time the
switch is turned ON, the number increases by 1 and the values between 1 and 30 can be set this
way. Buzzer sounds when data storing is complete.
c. Turn OFF the key switch.

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Reset example 3: Setting lifting magnet

a. Select the lifting magnet time using buzzer stop switch. (The selected item changes from negative
display to positive display.)

RST MODE II. H PA 0000

1
BRK 1 8 0 0 rpm AU 0000

L/M 0 0 0 0 rpm HLD 0000

AI 0 0 0 0 sec OUT 0000

b. Then, set the lifting magnet revolutions at 2000 min-1. Start the engine and adjust the engine
revolutions with throttle volume while observing the monitor. When adjustment is complete, leave the
operation mode switch ON for 10 seconds. Buzzer sounds when data storing is complete.
c. Turn OFF the key switch.
d. The setting can be verified through the CHK 1 engine revolutions.

Reset example 4: Changing the pump settings

a. Push buzzer stop switch for selecting PA (Selected item is shown with negative form positive
display.)

RST MODE II. H PA 0000 PA = 0: Normal mode

1
BRK 1 8 0 0 rpm AU 0000
PA = 1: Low power mode (-100mA)
PA = 2: Low power mode (-150mA)
L/M 0 0 0 0 rpm HLD 0000
PA = 3: Low power mode (-250mA)
AI 0 0 0 0 sec OUT 0000

b. To set pump power to low power mode, push travel mode switch until the number changes to one.
The number changes from 0 to 3-flop with pushing travel mode swich. After setting, push work mode
switch for ten seconds to keep the data. Then, buzzer sounds to notice the procedure is finished.
c. Turn OFF the ignition/main key.

Reset example 5: Setting the auto-boost OFF

a. Select auto-boost OFF using buzzer stop switch. (The selected item changes from negative display
to positive display.)

RST MODE II. H PA 0000 AU = 0: Auto-boost ON

1
BRK 1 8 0 0 rpm AU 0000 AU = 1: Auto-boost OFF

L/M 0 0 0 0 rpm HLD 0000

AI 0 0 0 0 sec OUT 0000

b. Then, set auto-boost OFF. Using travel mode switch, set the number at 1. Every time the switch is
turned ON, the number alternates between 0 and 1. When the setting is complete, leave the
operation mode switch ON for 10 seconds. Buzzer sounds when data storing is complete.
c. Turn OFF the key switch.

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Reset example 6: Altering settings that are retained in memory

a. Select Retain Previous Data using buzzer stop switch. (The selected item changes from negative
display to positive display.)

RST MODE II. H PA 0000

1
BRK 1 8 0 0 rpm AU 0000

L/M 0 0 0 0 rpm HLD 0000

AI 0 0 0 0 sec OUT 0000

HLD 0000
Auto mode (0 = Previous data retained, 1 = Previous data reset)
Operation mode (0 = Previous data reset, 1 = Previous data retained)
Travel mode (0 = Previous data reset, 1 = Previous data retained)
Service intervals display (0 = equipped with the function, 1 = not equipped with the function)

b. Then, set operation mode at Retain Previous Data. Using travel mode switch, set the number to 1.
Every time the switch is turned ON, the number alternates between

0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111

When the setting is complete, leave the operation mode switch ON for 10 seconds. Buzzer sounds
when data storing is complete.
c. Turn OFF the key switch.

Service due interval set

a. Push buzzer stop switch once more, monitor display changes RST2 and select 2.
1 ; Remaining time until “Service Due” message
RST MODE II. H 4 0000
2 is shown at the next time (In case of left,
1 0465 5 0000 remaining time is 465hrs.).
2 ; Current setting intervals of service due
2 2000 6 0000 (In case of left, message is shown every
3 0000 7 0000
500hrs.).
3-7; Blanlk
b. Push travel mode switch until the number changes to what you want. Every time when pressing
travel mode switch, values shown at 2 are switched as follows.
500 0050 0250 0500 1000 2000 5000 0050 0250 0500 .......(Default)

c. After setting, push work mode for ten seconds to keep the data. Then, buzzer sounds to notice the
procedure is finished.
d. Turn OFF the ignition/main key.

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MEASURING ELECTRICAL DEVICES First Edition: 09/2004

1. Instruments to Be Measured
A. Electromagnetic proportional valve of hydraulic pump
B. Stop motor
C. Solenoid valve
D. Backup sensor
E. Coolant temperature/Oil temperature sensor
F. Pressure sensor
G. Fuel sensor

2. Equipment for Measuring

A. Tester
B. Service connector kit assembly part No.:
A. For stop motor (6P) Part No.: WDB0055-3

B. For harness side of stop motor (6P) Part No.: WDB0055-4

C. For solenoid valve (2P) Part No.: WDB0055-5

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4. For electromagnetic proportional valve of hydraulic pump (2P) Part No.: WDB0055-6

5. For electromagnetic proportional valve of hydraulic pump (2P) Part No.: WDB0055-7

6. For pressure switch (2P) Part No.: WDB0055-8

7. For the harness side of pressure switch (2P) Part No.: WDB0055-9

8. For receiver dryer (2P) Part No.: WDB0055-10

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9. For oil temperature/coolant temperature sensors (2P) Part No.: KHP1575

10. For backup sensor (2P) Part No.: KHP1732

11. For pressure sensor (2P) Part No.: KHP1577

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MEASURING ELECTRICAL DEVICES First Edition: 09/2004

3. Measuring Methods
A. Electromagnetic proportional valve of hydraulic pump

CONNECTOR Connector
• Remove the connector on the electromagnetic proportional
valve that is attached to the hydraulic pump.

• Connect service connector 2P on the connector that was just

removed.
• Do not let the plug terminals cross at this point.

• Ensure the brown/black harness from the cab side is

selected (the service connector side has the same colors).
Connect tester's red terminal to the cab side, and the black
terminal to the hydraulic pump side.
• When connected properly, start the engine and check the
current of each mode at maximum revolutions.

Current for each mode

(mA)
Mode H Auto
S L
Model MAX MIN S L
SH290-3 415 305 305 Below 50 345 305

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B. Stop motor

• Remove the connector that is attached to the stop motor.

STOP MOTOR

CONECTOR

• Connect service connector 6P on the connector that was just

removed. (on cab side only)

• Ensure the blue/red harness from the cab side is selected

(the service connector side has the same colors). Connect
tester's red terminal to the cab side, and ground the black
terminal.
• When connected properly, turn the key switch ON and check
the voltage.

Voltage 24 V

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C. Solenoid valve (4-way)

• Remove a connector that is attached to the solenoid valve.

(The procedures here are given for lever lock solenoid.)

CONECTOR

• There are four solenoid valves. Refer to the illustration on the

left for intended use for each valve (viewed from the front).
Connectors have strips with different colors on them.
Be aware of the color-coded functions when measuring the
device.

• Connect service connector 2P on the connector that was just

removed (solenoid valve side only).

• Connect the red and black terminals to the plug terminal of

service connector.
• When connected properly, check the resistance.
Resistance 45 Ω (at 20°C)

Note: There will be slight variations in resistance depending on

the temperature.

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D. Backup sensor

• Remove the connector that is attached to the backup sensor.

BACKUP SENSOR

• Connect service connector 2P on the connector that was just

removed (rotational sensor side only).

• Connect the red and black terminals to the plug terminal of

service connector.
• When connected properly, check the resistance.
Resistance 0.7 Ω (at 25°C)

Note: There will be slight variations in resistance depending on

the temperature.

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E. Coolant temperature / oil temperature sensor

• Uninstall coolant temperature sensor or oil temperature sensor.

COOLANT TEMPERATURE SENSOR

OIL TEMPERATURE SENSOR

• Connect service connector 2P on the sensor that was just

uninstalled.
• Connect the red and black terminals to the plug terminal of
service connector.
• When connected properly, gradually increase the
temperature and check the resistance.

Temperature versus resistance

Units: kΩ
Coolant (Oil) Coolant Oil temperature
temperature temperature sensor sensor
20°C 6.08 2.45
30°C 4.24 1.66
40°C 3.02 1.15
50°C 2.18 0.81
60°C 1.61 0.58
70°C 1.20 0.43
80°C 0.91 0.32

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F. Pressure sensor
• Remove the connector on pressure sensor that is attached to the hydraulic pump.

PRESSURE SENSOR P2

PRESSURE SENSOR P1

PRESSURE SENSOR N1

• Connect service connector 3P on the connector that was just

removed.
• Connect the red terminal to the plug terminal YL (Yellow/
Blue) of service connector. Ground the black terminal.
• When connected properly, turn the key switch ON and check
the voltage.

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Voltage of pressure sensor

Pressure and Voltage

1. Pressure sensor for P 1, P 2

Formula for converting pressure: Pressure MPa Voltage (V)
1 MPa = 1.019 × 10 kgf/cm2
50 4.5
Example: 30 MPa = 30 × 1.019 × 10
43.7 4
= 305.7 kgf/cm2
2 MPa = 2 × 1.019 × 10 37.5 3
= 20.28 kgf/cm2 25.0 2
17.5 1
0 0.5

2. Pressure sensor for negative control

Pressure MPa Voltage (V)

5.0 4.5
4.37 4
3.75 3
2.5 2
1.25 1
0 0.5

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INITIAL CONTROLLER SETTINGS First Edition: 07/2001

1. Verifying the Settings

When the machine is started for the first time after having the settings reset (the resetting procedures will be
described later), the machine model, the operational locale and the specific language needs to be set again.
• Verifying controller settings/Resetting
The current settings will be displayed by pressing down the auto-mode switch for 10 seconds. (This is just
for verifying the settings and not for resetting them.)

2. Resetting Procedures
If the auto-mode switch is pressed down for another 10 seconds after the verifying state described in
1. Verifying the Settings, a buzzer will sound continuously.
Because the starter switch is turned off, the settings are all cleared. Now the controller is ready for resetting.
(By pressing the auto-mode switch for a shorter period of time (less than10 seconds) while settings are
displayed, display will switch to normal.)

3. Setting Procedures
When the starter switch is turned on after resetting the controller, the following will be displayed on the LCD
screen on the monitor.

By utilizing the travel mode switch, operation mode switch and the auto-mode switch on the monitor, select the
MACHINE, the TERRITORY and the LANGUAGE.

1. Each time the operation mode switch is pressed, the items alternate between MACHINE, TERRITORY
and LANGUAGE. (The selected item will be highlighted.)
2. Each time the travel mode switch is pressed, the individual setting in each item switches.
If MACHINE is selected, for example, the display will change as follows: SH120-3→SH200-3→
SH220-3→SH300-3→SH400-3...
When TERRITORY is selected, the display will switch as follows: 0→1→2→0→1→2... (0: for use inside
Japan)
When LANGUAGE is selected, the display will switch as follows: 0→1→2→...→13→14→0→1...
(0: Japanese).

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INITIAL CONTROLLER SETTINGS First Edition: 07/2001

3. As the auto-mode switch is pressed after the three items are reset, the settings are saved. Now the
resetting is complete and the display goes back to normal. (If set for domestic use in Japan, for
example, the display shows bar graphs after displaying PAX logo for 3 seconds.)
Once the MACHINE setting is complete, the machine does not display the screen for this setting any
more. The machine will start in normal display screen from the next time it is turned on.

4. List of Settings
MACHINE: SH120-3 SH250-3
SH150-3 SH300-3
SH180-3 SH400-3
SH200-3 SH800-3
SH220-3
TERRITORY: 0 . . . . . Domestic model (Japan)/General Export
models
1 . . . . . LBX
2 . . . . . CASE (North America)
3 . . . . . CASE (Europe)
4 . . . . . IHI
LANGUAGE: 0 . . . . . Japanese
1 . . . . . English
2 . . . . . Thai
3 . . . . . Chinese
4 . . . . . German
5 . . . . . French
6 . . . . . Italian
7 . . . . . Spanish
8 . . . . . Portuguese
9 . . . . . Dutch
10 . . . . Danish
11 . . . . Norwegian
12 . . . . Swedish
13 . . . . Finnish
14 . . . . Pictographs only

5. Error Display Functions

While setting the controller, the part number of the controller installed on the machine will be displayed on
LCD screen of the monitor.
When the wrong model is selected and an attempt is made to save this by pressing the auto-mode switch, a
buzzer sounds continuously and an error message will be displayed.
If this happens, the starter switch must be turned OFF once for further inputs to be accepted. Do this first, then
check the model and the part number of the engine controller. Turn the starter switch ON again and start the
setting procedures.

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TROUBLESHOOTING First Edition: 07/2001

1. Problem Symptoms
1. This section is on troubleshooting. If a warning message continues to be displayed even after taking the
appropriate measures suggested for the problem, refer to the procedures in this section.

Messages Displayed Problem Symptoms Problem No.

Refill fuel Message still showing after refilling fuel. 1
Refill coolant Message still showing after adding coolant. 2
Abnormal engine oil pressure Message still showing after oil pressure is 3
corrected.
Overheat Message still showing when the hydraulic oil 4
temperature is 84°C or below, or the engine
coolant temperature is 92°C or below.
Problem with battery charging Message still showing. 5
Faulty electrical system Message still showing. 6

2. The following is for troubleshooting a problem that does not get displayed on the monitor screen.
Engine controls:

Problem Symptoms Problem No.

Engine does not start Monitor indicates faulty electrical system. Refer to Problem No.
6.

Problem No. 7

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TROUBLESHOOTING First Edition: 07/2001

2. Inspections Prior to Troubleshooting

Item Criterion Remedies
GENERAL CHECKLIST
LUBRICANTS / 1. Check fuel level. — Add fuel.
COOLANT
2. Make sure fuel is not contaminated. — Clean/drain.
3. Check hydraulic oil level. — Add oil.
4. Check hydraulic oil strainer. — Clean/drain.
5. Check lubrication of each reduction gear. — Lubricate.
6. Check engine oil level (oil level in pan). — Add oil.
7. Check coolant level. — Add coolant.
8. Make sure dust indicator is not clogged. — Clean or replace.
ELECTRICAL DEVICES 9. Make sure battery terminal wiring is not — Tighten or
loose or corroded. replace.
10.Make sure alternator terminal wiring is not — Tighten or
loose or corroded. replace.
11.Make sure starter terminal wiring is not — Tighten or
loose or corroded. replace.
OTHER ITEMS TO BE CHECKED
HYDRAULICS / 12.Check for abnormal noise and odor. — Repair.
MECHANICAL DEVICES
13.Make sure there is no oil leakage. — Repair.
14.Bleed air. — Bleed air.
ELECTRICAL SYSTEM 15.Check battery voltage (with engine 23 to 36 V Replace.
OR DEVICES stopped).
16.Check battery electrolyte level. — Add or replace
electrolyte.
17.Check wires for discoloration or burning. — Replace.
Also check sheath for damage.
18.Check for disconnected wire clamps and — Repair.
hanging wires.
19.Make sure there is no water leakage onto — Disconnect to dry
wiring. (Pay particular attention to water in case there was
on connectors and terminals.) water on
connectors.
20.Check fuse for breakage or corrosion. — Replace.
21.Check alternator voltage (with engine 27.5 to 29.5 V Replace.
running at 1/2 throttle or higher). (When
battery is low, voltage may start around
25 V upon start-up.)
22.Check sound from battery relay (with — Replace.
starter switch both ON and OFF).

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Electric Circuits Page No. 3 /13

TROUBLESHOOTING First Edition: 07/2001

3. Troubleshooting Procedures
1. When a user contacts for repairs or problems, be sure
to get the following information.
a. User name
b. Machine type, Model No.
c. Work site

2. Get an understanding of the problem while you are

speaking with the user.
a. Status of the problem
b. Specific type of task/operation being performed
when the problem occurred
FAULTY DISPLAY ON FAULTY OPERATION? c. Work environment
MONITOR? 1. ENGINE d. History of past repairs and maintenance
1. WARNING MESSAGES 2. OPERABILITY
2. BAR GRAPHS

3. Get the required tools:

Crimp pliers (for plug terminals, for round-shaped
terminals)
Nipper
Plug terminals (for connection)*
*AJ wires including pins for connectors

4. Go to the work site, re-enact the incident and perform

the self-tests to check diagnosis on display.
a. Try operating each function/task on the machine to
verify the problem.
b. Check the self-test display.

5. Follow the 2. Inspections Prior to Troubleshooting to

determine the problems beforehand where possible
and to conduct simple repairs. Refer to:
a. General checklist
b. Other items to be checked

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TROUBLESHOOTING First Edition: 07/2001

4. Using the Flow Chart

1. Problem number and symptoms
The problem number and problem symptoms are provided above each flow chart.

Problem No. Problem Symptoms

1 Message still showing after refilling.
2 Message still showing after adding coolant.

2. About Inspection Prior to Troubleshooting

Check the items in the 2. Inspections Prior to Troubleshooting list before trying to determine the cause
of the problem.
3. Procedure
• Follow what the appropriate box says and perform inspection or take measurements. According
to the result, choose YES or NO to move on to the next part in the flow chart.
• If, as a result of checking or measuring, the YES or NO leads directly to the CAUSE column, refer
to the description under CAUSE and perform the troubleshooting procedures shown to the right.
• Inspection/measurement methods are described in the boxes.
• Choose YES if the situation matches the criteria or if the answer to the question is yes; NO if not.
• Required preparatory work, operational methods or criteria are provided below the boxes.
Skipping the preparatory procedures or not following the actual procedures properly may result in
damage to the machine. Thoroughly read all the related procedures before starting work. Also
start with the first procedure and follow the rest in the exact order of the book.
4. Wire colors
Refer to the table below for the wire colors of measuring locations. (The connector numbers will start on
the following page.)
Wire color chart

Symbol B W Br P V G O
Color Black White Brown Pink Purple Green Orange
Symbol R Y Lg Sb L Gr
Color Red Yellow Light green Sky blue Blue Gray
Note: Two letters combined (ex. AB) indicates a stripe color B on a wire color A.
Example: BR indicates red stripe on black wire.

5. Always turn OFF the key switch before connecting or disconnecting connectors.

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TROUBLESHOOTING First Edition: 07/2001

5. Diagnosis
A. Refilling fuel
Problem symptom
• Message still shows after refilling.

FUEL
CONTROLLE SENSOR
R

KEY SWITCH OFF

Troubleshooting Cause Remedy

Key switch ON
Run service support
CHK 4 to measure
resistance on
sensor. (Refer to Defective Replace
table below for controller controller.
resistance.)
Key switch OFF
Disconnect coupler
from sensor to
measure resistance
on the sensor side. Defective fuel Replace or
(Refer to table sensor check
sensor.
below for

Disconnect CN24
connector to mea-
sure resistance be-
tween female Loose Clean
terminal GL and connection on connector
GND (ground). (Re- fuel sensor terminal.

Disconnect CN1
connector to mea-
sure resistance be-
tween female Loose Clean
terminal GL and connection on CN24
GND (ground). (Re- CN24 connector

Defective Replace
controller or controller or
loose clean CN11
Note: Bar indicator lights will all be off when there is a break in wiring. connector

Resistance between GL and BG

Monitor 1 Refill fuel 2 3 4 5 6 7 8

Resistance (OHM) 80 to 75 75 to 61 61 to 47 47 to 37 37 to 30 30 to 24 24 to 19 19 to 10

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TROUBLESHOOTING First Edition: 07/2001

B. Refilling coolant
Problem symptom
• Message still shows after adding coolant.

RESERVO
IR LEVEL
SWITCH
CONTROLLE
R

Troubleshooting Cause Remedy

Key switch ON
Disconnect connector on
reservoir level switch to see if
message turns off.
Defective Replace
reservoir level reservoir.
switch

Disconnect CN24
connector to see if
message turns off. Short circuit on Repair wire
wire GrG GrG.
between
reservoir level
switch and

Disconnect CN4 connector

to see if message turns off.
Short circuit on Repair wire
wire GrG GrG.
between CN24

Defective Replace
controller controller.

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Electric Circuits Page No. 7 /13

TROUBLESHOOTING First Edition: 07/2001

C. Low engine oil pressure

Problem symptom
• Message still shows after correcting engine oil pressure.

OIL
PRESSURE
SWITCH
CONTROLLE
R

Troubleshooting Cause Remedy

Check 12 sec. after engine

Disconnect connector
on oil pressure switch to
see if message turns
off. Defective oil Replace.
pressure switch

Disconnect CN24
connector to see if
message turns off.
Short circuit on Repair wire
wire LgY LgY.
between oil
pressure switch
and CN24

Disconnect connector CN4

to see if message turns off.
Short circuit on Repair wire
wire LgY LgY.
between CN24

Defective Replace
controller controller.

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TROUBLESHOOTING First Edition: 07/2001

D. Overheat
Problem symptom
• Message still shows when the hydraulic oil temperature is 98°C or below and engine coolant
temperature is 105°C or below.
Precautions: Make sure that the bar indicator for coolant temperature or oil temperature is at 8.

ENGINE
CONTROLLER

THERMO-SENSOR
(COOLANT)
CONTROLLER

THERMO-SENSOR
(OIL)

Troubleshooting Cause Remedy

1) Bar indicator for coolant temperature is at 8.

Key Switch ON
Service support CHK 1 detects
abnormal indication of temperature
(coolant) by thermo-sensor (actual
temperature versus indicated
• Run CHK
1 WT to
display Verify that error code
coolant E0015 for coolant tem-
temperatur perature sensor is dis-
e. played on service
• Measure
actual
Disconnect connector on
thermo-sensor (coolant) to
measure resistance of
connector on the sensor Defective Replace
side. (Refer to table on thermo-sensor sensor.
(coolant)
Disconnect connectors
CN24 and CNA0 to mea-
sure resistance between Loose Clean
male terminals PL and connection on connector
BP. (Refer to table on next connector of terminal on
thermo-sensor sensor.
Disconnect connectors (coolant)
CN7 and CNA0 to mea-
sure resistance between
female terminals PL and Loose Clean CN24
BP. (Refer to table on next connection on connector
CN24 terminal.
Defective Replace con-
controller or troller, or clean
loose CN7 or CNA0
Note: Bar indicator lights will all be off when there is a break in wiring. connector ter-

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TROUBLESHOOTING First Edition: 07/2001

Troubleshooting Cause Remedy

2) Bar indicator for hydraulic oil temperature is

Service support CHK 1 de-

tects abnormal indication of
temperature (oil) by ther-
mo-sensor. (actual temper-
ature versus indicated
• Run CHK
1 OT to
display Verify that error code
coolant M0020 for oil
temperatur temperature sensor
e. is displayed on
• Measure service support error
actual

Disconnect connector
on thermo-sensor (oil)
to measure resistance Defective Replace
on the sensor side. (Re- thermo-sensor sensor.
fer to table below for re- (oil)

Disconnect connector
CN24 to measure re-
sistance between male Loose Clean
terminals OL and BO. connection on connector
(Refer to table below connector for terminal on
thermo-sensor sensor.
Disconnect connector
CN1 to measure
resistance between Loose Clean CN24
female terminals OL connection on connector
and BO. (Refer to table CN24 terminal.

Defective Replace
controller or controller
loose or clean
Note: Bar indicator lights will all be off when there is a break in wiring. CN1 con-

Sensor resistance
Note: Resistance may vary slightly depending on the temperature.
Unit: kΩ
Coolant (Oil) temperature Coolant temperature sensor Oil temperature sensor
20°C 6.08 2.45
30°C 4.24 1.66
40°C 3.02 1.45
50°C 2.18 0.81
60°C 1.61 0.51
70°C 1.19 0.43
80°C 0.91 0.32

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TROUBLESHOOTING First Edition: 07/2001

E. Battery charging
Problem symptom
• Message still shows.

KEY
BATTERY ALTERNATOR

HOUR

CONTROLLER ENGINE
CONTROL

START

Troubleshooting Cause Remedy

Hour meter is not Disconnect connector

functioning. CN1 to measure voltage NO
between female terminal Break in wire Re-wire or
WR and Ground. LgR between repair LgR.
10 V or above CN1 and CN22

Loose Clean CN1

connection on connector
CN1 or terminal or
defective replace
controller controller.
Disconnect connector on
alternator R terminal to
measure voltage Defective Replace
between alternator side alternator alternator.
and Ground.

Disconnect connector
CN22 to measure voltage
NO
between male terminal Break in wire Repair wire
LgR and Ground. LgR between LgR
CN22 and between
alternator, or CN22 and
loose alternator,
connection on or clean the
connector.

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TROUBLESHOOTING First Edition: 07/2001

F. Faulty electrical system

Problem symptom
• Message still shows.
2-SPEED
TRAVEL

BOOST
BRAKE
SWING
LEVER
LOCK

ELECTRONIC GOVERNOR

SENSOR
BACKUP

ENGINE
ELECTROMAGNETIC PROPORTIONAL VALVE

ENGINE CONTROLLER
BATTERY RELAY

FUSE
LIMIT SWITCH

CONTROLLER

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Electric Circuits Page No. 12 /13

TROUBLESHOOTING First Edition: 07/2001

Troubleshooting Cause Remedy

Check the error type by service support error diagnosis

Key Switch ON
Problem detected in DIAG 1 To DIAG 4

E0031 displayed Faulty circuit Check

inside governor electronic
Faulty servo governor.

E0032 displayed Problem with Same as

rack sensor above.
signal inside

E0041 displayed Problem with Same as

TDC sensor above.
signal
Problem detected in DIAG 4

M00B0 Wrong engine Replace

controller engine

M0010 Check transistor circuit.

To CHK 2

Short circuit detected by auto

Message goes off when solenoid valve connector is disconnected. Defective Replace
solenoid valve solenoid
valve.

Message goes off when CN22 connector is disconnected. Short circuit on Fix wiring.
wire between
CN22 and

Message goes off when CN23 connector is disconnected. Short circuit on Fix wiring.
wire between
CN23 and

Message goes off when CN6 connector is Short circuit on Fix wiring.
wire between
CN23 and CN6

Message goes off when CN5 connector is disconnected. Short circuit on Fix wiring.
wire between
CN22 and CN5
Defective Replace
controller controller.

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Electric Circuits Page No. 13 /13

TROUBLESHOOTING First Edition: 07/2001

G. Engine controls
Problem symptom
• Engine does not start although there is no indication of faulty electrical system on display.
Check to ensure the following first:
• That the engine and the fuel gauge function properly
• That fuses are not blown out
• That starter motor is running and engine is cranking
SHUTDOWN RELAY
STOP MOTOR

EMERGEN
CY STOP SERVICE
CONNECTOR
CAB SIDE

FUSE

Troubleshooting Cause Remedy

Key Switch ON
Fuel cut lever is Faulty engine Check
positioned on the stop system engine
side. system.

Disconnect connector (CND6) on

stop motor to measure the Break in wire LR Fix wire LR.
voltage between between stop
(-) on Ground and (+) on LR that motor connector
connects the service connector and CN, or
break in wire
LR between
Disconnect connector on stop fuse and CN
motor and connect connector
on female side. Defective stop Replace
Check continuity between L motor stop motor.
and LW.
Key switch ON: continuity

Measure voltage between (+)

connector L on shut down relay
and (-) on Ground. Defective Replace
shutdown relay shutdown
Emergency stop button ON: 0 V relay.
Emergency stop button OFF: 20-

Break in wire L Replace

You can also check for connecting to shutdown
defective relays by shutdown relay relay or fix
replacing relays in the wiring L.
aggregated relay.

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Electrical Components and Wiring for Upper Frame
Electric Circuits Page No. 1/ 2

ELECTRIC WIRING DIAGRAMS First Edition: 09/2004

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Electrical Components and Wiring for Cab
Electric Circuits Page No. 2/ 2

ELECTRIC WIRING DIAGRAMS First Edition: 09/2004

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 290-1-04-08 -15
Upper Frame
Electric Circuits Page No. 1/ 2

HARNESS DIAGRAMS First Edition: 09/2004

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Inside Cab
Electric Circuits Page No. 2/ 2

HARNESS DIAGRAMS First Edition: 09/2004

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Maintenance Page No. 1/ 2

NEW MACHINE PERFORMANCE First Edition: 09/2004

1. Performance Evaluation Check Sheet

= Confirmation, S = Measurement, A = Adjustment

Inspection Item Confirm Remarks Inspection Item Confirm Remarks

Fluid/Oil Level Inspection Engine inspection

1. Radiator fluid level 1. Number of engine revolutions
Idling min-1
2. Engine oil level Maximum with no load min-1
3. Hydraulic oil level 2. Conditions of engine rotation
Brake-in Operation Inspection When idling (As
1. Engine start/stop Without load required)
2. Air bleeding 3. Engine exhaust hue
3. Individual operation 4. Engine sound and vibration
4. Oil leakage 5. Engine stop
Turning off the key switch
Hydraulic Oil Contamination Emergency stop switch
Inspection
Hydraulic Equipment Inspection
Electrical System Inspection
1. Pressure of each component
1. Machine type choice (refer to separate sheet)
2. Indicator lights 2. Abnormal sounds of each part
3. Monitor display (1) 3. Natural lowering level of each
cylinder (refer to separate
4. Monitor display (2) sheet)
5. Mode change functions 4. Operation speed of each
6. One-touch/Auto idle function cylinder (refer to separate
sheet)
7. Lever lock function (As
5. Swing speed (refer to separate
8. Swing brake function sheet) required)
9. 2-speed travel function 6. Swing brake performance (refer
to separate sheet)
10. Swing lock function
7. Condition and sound of swing
11. Travel alarm function motions
12. Auto glow (GT) 8. Travel speed (refer to separate
13. Power shut-off delay function sheet)
1. Accessories operation 9. Turns
Radio 10. Condition and sound of
Air conditioning travelling
Windshield wiperblades
Vehicle horn Operation Inspection
Working light 1. Operation condition of each
Interior lights lever
Clock Shoe Tension
Hour meter
Backup lights Others
1. Oil leaks at each part
2. Oil leaks at rubber hoses or
piping
3. Looseness or fall off of bolts
and nuts
4. Cab inspection
5. Cylinder inspection
6. Nephron filter inspection

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Maintenance Page No. 2/ 2

NEW MACHINE PERFORMANCE First Edition: 09/2004

2. Performance Evaluation Recording Sheet

Evaluation Date
Model of Machine: Model Number: Evaluated by
(mm/dd/yy)
Attachment
Hour Meter: Remarks
Arm m3 Bucket
No. of idling revolutions min-1
No. of engine
1 Maximum number of revolutions
revolutions min-1
without load
Relief Name Operation Measured pressure

Pressure check of Standard MPa

Main relief
each component Boosting MPa
2 (Evaluate as required) Swing port relief Left/Right MPa
Pilot relief — MPa
For measurement and adjustment methods, refer to procedures for hydraulic oil pressure measurement and
adjustment in Service Manual.
Boom cylinder mm
Drift for each cylinder Arm cylinder mm
3
(5 minutes) Bucket cylinder (when open) mm
Overall (10 minutes) mm
1st 2nd 3rd
Total Average
Reading Reading Reading
Up
Boom
Operation speed Down
4 for each cylinder
Out
(sec) Arm
In
Open
Bucket
Closed
1st 2nd 3rd
Total Average
Swing speed Reading Reading Reading
5
(sec/1 revolution) Swing Left
Swing Right
1st 2nd 3rd
Swing angle 180°, neutral brake flow angle Total Average
6 Reading Reading Reading
(degrees)

1st 2nd 3rd

Total Average
Travel speed Reading Reading Reading
7
(sec/6 m) Forward
Reverse
1st 2nd 3rd
Total Average
Reading Reading Reading
Number of Front low
8 drive sprocket revolutions
Back low
(sec/10 revolutions)
Front high
Back high
Horizontal mm
9 Degree of turntable bearing shift
Vertical mm
Amount of shoe tension ranging from the bottom side frame to
10 mm
shoe surface

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Maintenance Page No. 1/ 1

NEW MACNINE PERFORMANCE First Edition: 09/2004

Reference Values
Numerical values for performance may change without notice due to product improvement.
Items SH290-3

Number of engine Idling 1,000 ± 20

1 Mode: H
revolutions (min-1) Maximum without load 2,250 ± 20

Standard 34.3 +0.3

-1.0
Main Relief
Pressure of each part Boosting 37.3 +0.3
-1.0
2 Mode: S
(MPa)
Swing port relief Vertical 29.9 ± 0.5
Pilot port relief 3.9 ± 0.2
Boom cylinder 5 or below

Natural lowering level of Arm cylinder 5 or below No load for five minutes
3
each cylinder (mm) Bucket cylinder (when open) 7 or below
Overall 225 or below No load for 10 minutes

Boom (when Up 4.4 ± 0.5

bucket is open) Down 3.2 ± 0.5

Operational speed of Open 2.8 ± 0.5

4 Arm Mode: S
each cylinder (sec) Close 3.8 ± 0.5
Open 2.6 ± 0.6
Bucket
Close 4.9 ± 0.5
5 Swing speed (sec/1 revolution) 7.3 ± 0.5 Mode: S
6 Swing angle 180°, neutral brake flow angle (degrees) 45°or below Mode: S
7 Travel speed (sec/6 m) High 4.6 ± 0.5 Mode: S

Number of drive sprocket revolutions High 17.7 ± 0.6

8 Mode: S
(sec/10 revolutions) Low 30.0 ± 0.7
Horizontal 5.0 or below
9 Amount of turntable bearing shift (mm) Mode: S
Vertical 1.5 or below
Amount of shoe tension ranging from the side frame bottom to
10 270 ∼ 300
shoe surface (mm)

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Maintenance Page No. 1/ 3

MAIN BODY WEIGHT First Edition: 09/2004

1. Major Component Weight (Standard specifications)

Weight* (kg)

Symbol Component Name SH290-3

A Operating weight 28,400
B Upper structure (including counterweight and 11,550
turntable bearings)
C Counterweight 5,410
D Bottom structure (with grouser shoe) 11,620
E Machine weight 23,170
F Attachments 5,150
G Boom (including cylinder) 3,000
H Arm (including cylinder and linkage) 1,350
* The weight information is approximate.

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Maintenance Page No. 2/ 3

MAIN BODY WEIGHT First Edition: 09/2004

2. Individual Part Weight

Dry weight for each part is shown in the table below. Weight (kg)

Part Name SH290-3

1 Travel unit 365
2 Take-up roller 154
3 Upper roller 43
4 Lower roller 60
5 Swing unit 428
6 Turntable bearing 498
7 Engine 487
8 Radiator 165
9 Hydraulic pump 139
10 Fuel tank 85
11 Sump tank 121
12 Control valve 187
13 Rotating joint 29
14 Boom 1,899

3. Shoe Weight (One side)

Weight (kg)

Part Name SH290-3

1 600 mm grouser shoe 2,191
2 700 mm grouser shoe 2,387
3 800 mm grouser shoe 2,595

4. Arm Weight
Weight (kg)

Part Name SH290-3

1 Standard arm (3.20 m) 850
2 Short arm (2.67 m) 747
3 Long arm (3.66 m) 948

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MAIN BODY WEIGHT First Edition: 09/2004

5. Bucket Weight
SH290-3

Bucket Capacity (m3) Weight (kg) L1 (mm) L2 (mm)

1 1.0 829 1,175 1,255
2 1.1 846 1,230 1,331
3 1.3 908 1,410 1,511

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 290-1-05-04 -13
Maintenance
Maintenance Page No. 1/ 1 Attachments Dimensions
ATTACHMENTS DIMENSIONS First Edition: 09/2004

T
MAX. RETRACTED LENGH
STROKE

BOSS OF ARM POINT BUCKET LINK

Region Arm Bucket Arm Bucket Link

Link
Model A B C D E F G H I J1 J2 K1 K2 L1 L2 M1 M2 N O P Q R S T U1 U2
SH290-3 3,190 804 460 556.9 280 250 729.8 190 150 90 80 325 316 485 515 326 326 90 468 620 605 325 106 316 90 90

BUCKET PIN

Region Bucket Pin Bucket Cylinder

Bucket and arm mounting section Bucket and bucket link mounting section Max. Width at top
Stroke
Model V W X Y V W X Y retracted length section

SH290-3 90 90 528 21 90 90 474 21 1,665 1,073 105

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Maintenance Page No. 1 /14

INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

1. Measuring Pressure
A. Basic conditions
Model
SH290-3
Condition
Operation mode S Mode
Oil temperature 45 to 55°C
No load engine revolutions 2,050 ± 10 min-1

B. Set values
The values below are measured on an actual machine and are not standard values.

Relief valve set pressure Values measured on Measuring

(as single component) actual machine methods

Main relief Standard 34.3 ± 0.3 MPa at 156 L/min 34.5 MPa Arm relief
pressure Power boost 37.3 ± 0.5 MPa at 136 L/min 37.5 MPa Arm relief
Fastening main
Up 39.2 ± 0.5 MPa at 20 L/min 40.0 MPa relief 180° +
Boom port Boom up relief
relief
↑ + Boom down
Down 39.2 ± 0.5 MPa at 20 L/min 40.0 MPa
relief
Arm In/Out port relief 39.2 ± 0.5 MPa at 20 L/min 40.0 MPa ↑ + Arm relief
Bucket Open/Close port relief 39.2 ± 0.5 MPa at 20 L/min 40.5 MPa ↑ + Bucket relief
Swing relief 29.4 ± 0.4 MPa at 217 L/min 29.0 MPa Swing relief
Pilot relief 3.9 ± 0.1 MPa 3.7 MPa Lever neutral

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Maintenance Page No. 2 /14

INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

C. Pressure measuring port

Main pressure
A pressure sensor is mounted on the pump of Model 3 and the circuit pressure can be displayed on the
monitor (except for pilot pressure).

PRESSURE SENSOR P2

PRESSURE SENSOR P1

PRESSURE SENSOR N1

Pressure on each relief valve (except for pilot pressure) can be confirmed on the monitor display.
1. How to display the pressure on the monitor display
Use the mode-changing switch on the monitor display to display the pressure.
Monitor and switch panels

How to operate

Operating button Monitor display

Travel and Work Mode

Press the switch for at least 3 seconds.

P1 indicates the front pump pressure and P2 the

rear pump pressure.
Units are MPa (mega pascal).

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Maintenance Page No. 3 /14

INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

2. Pilot pressure
When the right side cover is opened, there are an accumulator and pilot filter mounted in front of the
counterweight. Remove the Rc1/8 blank plug, which is an L shaped joint attached to the manifold, and
measure pressure.

Rc1/8 PILOT PRESSURE

MEASURING PORT

PILOT FILTER

ACCUMULATOR

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Hydraulic Circuits Page No. 4 /14

INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

D. Preparation for measuring pressure

1. Items to prepare
• Pressure gauge For 9.8 MPa use
• Tools Spanner (closed wrench) 17 mm
Hexagonal wrench 6 mm
• Other Cloth, Cleaning solution

2. Monitor check
• In the Service Check, check the engine maximum
revolutions with no load and the input current value of the
pump in S mode.

Maximum Engine S Mode

Revolutions current value
SH290-3 2,050 ± 10 min-1 305 mA
(when operating)

3. Machine positioning
• Position the machine on solid level ground, lower the
boom allowing the arm end to touch the ground with the
bucket cylinder OUT at stroke end and the arm cylinder
OUT at stroke end.

4. Pressure relief in circuit

• Turn off the ignition key and confirm the engine has
stopped. Turn on the key again.

Note: Do not start the engine.

• Operate each lever more than 10 times and make sure

that the attachments do not move. Then, turn off the key.

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Hydraulic Circuits Page No. 5 /14

INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

5. Pressure relief in hydraulic oil tank

• Press the air breather button, located on the hydraulic oil
tank, to release the pressure in the tank.

6. Install pressure gauge

PORT Rc1/8 • Install a pressure gauge to the pilot pressure measuring
port.
Pressure gauge For 9.8 MPa use
Port size Rc1/8

7. Check oil temperature

• Following the Service Check, confirm hydraulic oil
temperatures.

Oil temperature 45 to 55°C

• If the oil temperature is low, follow the instructions for

warming up in the Operator’s Manual to increase the oil
temperature.

Now, the preparation is completed.

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

E. Measuring pressure

1. Pilot relief pressure

Lever operation Neutral
PORT Rc1/8
Pressure gauge For 9.8 MPa use
Set pressure 3.9 ± 0.1 MPa

2. Main relief pressure

Lever operation Arm IN relief
The value is displayed on the monitor display.
See C. Pressure Measuring Port
Check P1 and P2 on the monitor display.
• Standard set pressure 34.3 ± 0.3 MPa
After relieving arm in, the power boost is displayed for 8
seconds and then the pressure goes down to standard.
Read the value.
• Power boost set pressure 37.3 ± 0.3 MPa
About 2 seconds after starting relieving, the power boost
set pressure is displayed for 8 seconds. Read the value.

3. Swing port relief pressure

The pressure on the swing motor Lever operation Swing relief
is displayed in P1 section on the The value is displayed on the monitor display.
monitor display.
Set pressure 29.4 ± 0.4 MPa
When measuring pressures while swinging, the
measurement should be carried out after activating the
mechanical brake by pushing the swing lock switch to lock
the swing.
Note: Press the swing lock switch and decrease the
engine revolutions to about 1000 min-1 when first
operating the swing lever. After making sure that the
swing does not move, increase the engine
revolutions to the maximum.

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4. Other port relief pressure

Lever operation: Put the attachments to be measured in a relieved condition.
The value is displayed on the monitor display.
Temporary adjustments are required because the port relief pressure of the attachment is higher than
the pressure for the main relief.
Refer to 2. Adjusting Pressure.

Boom Boom Arm Arm Bucket Bucket

Down Up Out In Open Closed
Measured pressure 39.2 ± 0.5 MPa
Where displayed P2 P2 P1 P1 P2 P2

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

F. Measuring other pressures

Secondary pressure on the electromagnetic proportional pressure reduction valve of the hydraulic pump

PORT a4(G1/4)

MOD
E

H CURRENT (mA) Max. 470

SECONDARY
PRESSURE 1.48
(MPa)
S CURRENT (mA) 410
SECONDARY
PRESSURE 1.92
(MPa)
MEASURING CONDITIONS:
NO LOAD ENGINE MAXIMUM REVOLUTION

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

2. Adjusting Pressure
A. Pressure Adjusting Points
1. Control valve

Tool used
Measuring Adjusting screw
Adjusting Set pressure
port Lock nut per turn
screw
a Main standard Monitor P1 27 27 34.3 ± 0.3 MPa 21.3 MPa
b Main power boost Monitor P1 32 27 37.3 ± 0.5 MPa 28.4 MPa
Boom UP
Monitor P2
Boom DOWN
Arm OUT Hexagonal
Monitor P1 17 wrench 39.2 ± 0.5 MPa 21.2 MPa
Arm IN 6 mm
Bucket OPEN
Monitor P2
Bucket CLOSE

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

2. Hydraulic pump

3. Swing motor

Tool used
Measuring Adjusting screw
Adjusting Set pressure
port Lock nut per turn
screw
Hexagonal
Pilot P3 24 wrench 3.9 ± 0.1 MPa 1.56 MPa
6 mm
Hexagonal
Monitor
Swing motor 41 wrench 29.4 ± 0.4 MPa 4.8 MPa
P1
14 mm

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

B. Instructions for adjusting pressure

1. Pilot pressure
Engine rpm S Mode maximum revolutions
PILOT RELIEF VALVE
Lever operation Neutral
Oil temperature 45 to 55°C
Tools Spanner 24mm
Hexagonal wrench 6 mm
Measuring port Joint close to accumulator
Pressure gauge For 9.8 MPa use
used
Set pressure 3.9 ± 0.1 MPa
PORT (Rc1/8)
Instructions for adjusting pressure:
a. Loosen the lock nut on the pilot relief.
b. Adjust to the set pressure by fastening the adjusting
screw.
c. Secure the adjusting screw with wrench and fasten the
lock nut.
d. After locking, check the pressure once again.

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

2. Main relief pressure

Engine rpm S Mode maximum revolutions

Lever operation Arm IN relief
Oil temperature 45 to 55°C
Tools Spanner 27 mm (2),
Spanner 32 mm (1)
Measuring port Monitor P1
Set Standard
34.3 ± 0.5 MPa
pressure pressure
Power
37.3 ± 0.5 MPa
boost
Pressure adjusting instructions
Before adjusting, install main relief valve.
Remove power boost signal pilot hose and plug the hose
side.
Power boost
a. Loosen standard lock nut 27, tighten adjusting
screw 27. Fasten it with spanner 27 mm so that the
power boost adjusting screw does not turn.
b. After tightening the adjusting screw until it will no
longer turn, tighten the lock nut.
c. Start the engine and run it at the maximum
revolution.
d. Put the arm lever into IN to bring it to relief condition
and hold it.
e. Loosen the power boost lock nut 32 and adjust it at
a set pressure with adjusting screw 27.
• If it is lower than the set pressure, tighten it.
• If it is higher than the set pressure, lower it once
and adjust by tightening it.
f. After adjusting pressure, secure the adjusting
screw with spanner 27 mm and fasten the lock nut.
g. After locking it, check the pressure at the power
boost side.
If a desired value has not been achieved, repeat
steps e and f.
Standard
Rechecking
h. Loosen the standard lock nut.
m. Start the engine, press the right lever power boost
i. Loosen the adjusting screw to lower the pressure
switch with the engine at maximum revolution and
below the set pressure and adjust it by tightening it.
verify no oil leakage at the adjusting area.
j. After adjusting pressure, secure the adjusting
n. Set the arm in relief condition at the arm IN side
screw with a spanner and fasten the lock nut.
and check standard pressure. Then press the
k. After locking it, check the pressure.
power boost switch and check the power boost.
If a desired value has not been achieved, repeat
o. If a desired pressure has not been achieved, repeat
steps h, i and j.
the steps starting at a.
l. Stop the engine.

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INSTRUCTIONS FOR MEASURING AND ADJUSTING PRESSURE First Edition: 09/2004

3. Port relief pressure

Engine rpm S Mode maximum

revolutions
Oil temperature 45 to 55°C
Tools Hexagonal wrench 6 mm
Spanner 17, 27, 32 mm
Measuring port Monitor P1
Set pressure 39.2 ± 0.5 MPa

Note: It is necessary to temporarily set the main relief

pressure higher than the port pressure because the
port relief pressure is set higher than the main relief
pressure.

Main relief pressure temporary setting

a. Loosen the power boost lock nut, and fasten the power
boost adjusting screw 180° and tighten the lock nut.
b. After adjusting port relief pressure, loosen power boost
lock nut and also loosen power boost adjusting screw
180° or greater to lower the pressure below the standard
set pressure. Then adjust by tightening it.
Note: Standard adjusting screw cannot be used for
adjustment.

Note: Power boost adjusting screw should be used for

adjustment. However, the set pressure is measured
at the standard pressure side.

Pressure adjustment
The port relief pressure for the boom, arm and bucket
should be adjusted referring to the previous section 1.
Control valve in the A. Pressure adjusting points.
After the adjustment is completed, the main relief
pressure should be set at a standard pressure.
For set pressure of each port, refer to set pressures in the
previous section.

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4. Swing motor relief pressure

Swing lock instructions
Press the swing lock switch located on the right-
hand switch panel in the cab and confirm that the
lamp next to the switch is turned on.
When the swing lever is first put in place, the engine
revolutions should be reduced to about 1000 min-1.
After making sure that the swing does not move,
increase the engine revolutions to the maximum.

5. Swing motor relief pressure

Engine revolutions S Mode maximum revolutions

Oil temperature 45 to 55 °C
Tools Hexagonal wrench 14 mm
Spanner 41 mm
Set pressure 29.4 ± 0.4 MPa

a. Check the current set pressure.

b. If the set pressure is different from the current pressure,
adjust the adjusting screw.

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COMPATIBILITY First Edition: 09/2004

List of Compatibility of Main Parts (SH240-3 and SH290-3 and SH330-3)

Part Name SH240-3 Compatibility SH290-3 Compatibility SH330-3

Travel unit KBA10060 ←×→ KBA1319 ←×→ KSA1322

600mm Grouser KBA1290 ←×→ KBA10020 ←×→ KSA1120

Link KBA1295 ←×→ KBA10050 ←×→ KSA1124

Shoe KBA0839 ←×→ KSA1121 ←○→ ←

Lower roller KBA1123 ←×→ KSA1068 ←○→ ←
Upper roller KRA1717 ←×→ KBA1141 ←○→ ←
Take-up roller KRA1767 ←×→ KSA1064 ←○→ ←
Recoil spring KRA1776 ←×→ KSA1297 ←○→ ←
Drive sprocket KRA1665 ←×→ KSA1061 ←○→ ←
Rotating joint → ←○→ KRA1875 ←×→ KSA1305

Counter weight KBB0722Y1 ←×→ KBB0836Y1 ←×→ KSB0850Y1

Turntable bearing KBB10080 ←×→ KBB10100 ←×→ KSB10070

Swing motor KBC0109 ←×→ KBC0120 ←×→ KSC0231

motor KBC0108 ←×→ KBC0155 ←×→ KSC0247

reduction gear KBC0154 ←×→ KSC0253 ←○→ ←

Engine KBH1009 ←×→ KBH1010 ←×→ KSH1012

Radiator KBH1002 ←×→ KBH0890 ←×→ KSH0893

Air cleaner KRH1569 ←×→ KBH0886 ←×→ KSH0895

Element (outer) → ←○→ KBH0921 ←×→ KSH0933

Element (inner) → ←○→ KBH0922 ←×→ KSH0932

Muffler KBH0848 ←×→ KBH0893 ←×→ KSH0948

Fuel tank → ←○→ KRH1352 ←×→ KSH0903

Hydraulic pump KBJ2789 ←×→ KBJ2895 ←×→ KSJ2851

Control valve KBJ10200 ←×→ KBJ3023 ←×→ KSJ3106

Remote control valve (for operation) → ←○→ KRJ5804 ←○→ ←

Remote control valve (for travel) → ←○→ KRJ5803 ←×→ KNJ2557

Sump tank → ←○→ KRJ6216 ←×→ KSJ3081

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COMPATIBILITY First Edition: 09/2004

Part Name SH240-3 Compatibility SH290-3 Compatibility SH330-3

Oprator’s cab → ←○→ KHN10020 ←○→ ←

Operator’s seat → ←○→ KHN3470 ←○→ ←
Console box → ←○→ KHN3237 ←○→ ←
Controller → ←○→ KHR2678 ←○→ ←
Monitor display → ←○→ KHR3826 ←○→ ←
Boom KBV1638 ←×→ KBV1915 ←×→ KSV1499

Arm KBV1644 ←×→ KBV1921 ←×→ KSV1506

Bucket (1.0m3) → ←○→ KBV1498 ←×→ ―

Bucket link → ←○→ KBV1655 ←×→ KSV1410

Arm link (RH) → ←○→ KBV1337 ←×→ KSV1319

Arm link (LH) → ←○→ KBV1338 ←×→ KSV1320

Boom cylinder (RH) KBV1543 ←×→ KBV1688 ←×→ KSV1393

Boom cylinder (LH) KBV1544 ←×→ KBV1689 ←×→ KSV1394

Arm cylinder KBV1545 ←×→ KBV1897 ←×→ KSV1395

Bucket cylinder KBV1546 ←×→ KBV1790 ←×→ KSV1396

Part numbers are for referense only. When you place a parts order, plase consult and comfirm with your
parts manual.

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APPENDIX First Edition: 07/2001

Unit Conversion Table

— (X) →
Gravitational unit SI units
← (÷) —
Kgf 9.807 N
Ibf 4.448 N
Kgf·cm 0.0981 N·m
Ibf·ft 1.356 N·m
Ibf·in 0.113 N·m

kgf/cm2 0.0981 MPa

atm 0.1013 MPa

Ibf·in2 0.0069 MPa

mmHg 133.3 Pa
inHg 3386 Pa
Kgf·m/s 0.00981 KW
Ibf·ft/s 0.00136 KW
PS 0.7355 KW
HP 0.746 KW
Kgf·m 9.807 J
Kcal 4186 J

Kgf·s/cm2 98067 Pa·s

cP 0.001 Pa·s
P 0.1 Pa·s
cSt 1 x 10-6 m2/s
St 0.0001 m2/s

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APPENDIX First Edition:07/2001

New Hydraulic Oil

Long-life hydraulic oil (IDEMITSU Daphne Super Hydro 46SX)
Features
Currently used oil
Zinc (referred as Zn-DTP afterwards) is used in the abrasive resistant hydraulic oil (Zn type hydraulic
oil), which is currently used, as a wear prevention agent (extreme pressure additive agent) and anti-
oxidation agent. However, it is prone to thermally decompose rapidly and generate sludge since in
recent years hydraulic devices have become smaller and use higher pressure. As a result, it
becomes impossible to use these devices for a long period because there is a risk of failure
occurrence such as filter blockage, sludge substance accumulation at the bottom of the tank,
misoperation of control valves, quicker wear in devices, etc.
About new hydraulic oil
Two types of additives are used: one is an anti-wear agent that generates less thermal-decomposed
sludge, the other is an anti-oxidation agent that controls partial oxidation deterioration at high
temperatures. Because of the usage of these additives, heat resistance and oxidation stability have
improved two or more times as much as the ones for the currently used oil. In addition, other
performance such as lubricating and defoaming characteristics have maintained the same or higher
level as the ones for the currently used oil. By achieving this, the life has been extended.

1. Reduced sludge generation

Adopted non-zinc type additives which 2. Low copper corrosion
have excellent heat resistance As a result, the extended exchange
period has been realized.

Table 1. The Results of High Pressure Circulation Deterioration Test (Source: IDEMITSU Test Results)

mg / 100 mL mg KOH / g

New hydraulic New hydraulic

oil oil

Changes in sludge generation over time Changes in total oxidation over time

The life of hydraulic oil is usually determined by the changes in three factors below:
1. Changes in kinematic viscosity over time (No significant difference is found between new
hydraulic oil and currently used oil.)
2. Changes in total oxidation over time (Considerable improvement has been made. See Table 1)
3. Changes in sludge generation over time (Considerable improvement has been made. See
Table 1)
To evaluate the heat resistance and oxidation stability of hydraulic oil, high pressure circulation tests
are generally used. Judging from the results above, it can be concluded that the new hydraulic oil
has a life period twice as long as the one for the currently used oil.
Note: If new oil is mixed with 10% or more of the currently used oil (MOBILE DTE25B), its properties will
turn back to the ones of the currently used oil.

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