SECTION 2 STRUCTURE AND FUNCTION

Group 1 Pump Device ------------------------------------------------------------------------------------------------------ 2-1

Group 2 Main Control Valve --------------------------------------------------------------------------------------------- 2-17
Group 3 Swing Device ------------------------------------------------------------------------------------------------------ 2-51
Group 4 Travel Motor -------------------------------------------------------------------------------------------------------- 2-60
Group 5 RCV Lever ---------------------------------------------------------------------------------------------------------- 2-70
Group 6 Accelerator Pedal ----------------------------------------------------------------------------------------------- 2-77
Group 7 Brake Device ------------------------------------------------------------------------------------------------------ 2-78
Group 8 Transmission ------------------------------------------------------------------------------------------------------ 2-80
Group 9 Travel Control Valve ------------------------------------------------------------------------------------------- 2-87
Group 10 Steering Valve ---------------------------------------------------------------------------------------------------- 2-89
Group 11 Front Axle and Rear Axle ---------------------------------------------------------------------------------- 2-91
 SECTION 2 STRUCTURE AND FUNCTION
GROUP 1 PUMP DEVICE

1. STRUCTURE
The pump device consists of main pump, and steering pump.
S L2
X

S1

T1 A

Main pump M G Steering pump

T1 M G

T2 M1 L1 X1 140WA2MP01

Port Port name Port size

A Service port 1"
S Suction port 3"
T1 Tank port 1 1/16-12UN
T2 Tank port 1 1/16-12UN
M1 Measuring stroking chamber 9/16-18UNF
M Measuring service line 9/16-18UNF
R Air bleed port -
G Control pressure port 9/16-18UNF
X Pilot pressure port 9/16-18UNF
B Service port 1 5/8-12UN
S1 Suction port 1 9/16-12UN
L1 Case drain port 3/4-16UNF
L2 Case drain port 3/4-16UNF
X1 Load sense port 7/16-20UNF

2-1
2. SCHEMATIC
1) MAIN PUMP

140WA2MP02

X2

T1 GM A
High pressure

Vg max Vg min
Control pressure Low pressure

Suction pressure Case pressure

R T2 M1 S
2-2
2) STEERING PUMP

B X

S0

High pressure Low pressure

DR

Suction pressure Leakage pressure

Pilot pressure Control pressure

S L1 L2
140WA2MP03

2-3
3. PART LIST
1) MAIN PUMP (1/2)

1 2 3 4 5 6 7 8 9 10 11 12 13

25

14 15 16 17 18 19 20 21 22 23 24

140WA2MP04

1 Prop. solenoid 10 Spring cup 19 Bolt

2 Control housing 11 Screw plug 20 Spring bolt
3 Pin 12 Sealing nut 21 Spring cup
4 Control piston LS 13 Set screw 22 Set screw
5 Control bushing LS 14 Prop. solenoid 23 Sealing nut
6 Bushing 15 Spring cup 24 Seal screw
7 Orifice 16 Spring 25 Screw plug
8 Spring cup 17 Spring cup
9 Spring LS 18 Control piston LR

2-4
 MAIN PUMP (2/2)

33 34 35 36 37 38 39 40 41

42
43
44
45
46
47
26

27
28
48

29

30 49
31

32

50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

140WA2MP05

26 Snap ring 39 Spring 52 Cage pair

27 Locking ring 40 Bushing 53 Retaining plate
28 Cylinderical roller bearing 41 Adjusting bushing small 54 Retaining ball
29 Drive shaft 42 Bolt 55 Cup spring stack
30 Snap ring 43 Angle lever 56 Adjusting screw
31 Shaft seal ring 44 Measuring roll 57 Piston pad
32 O-ring 45 Orifice 58 Sealing nut
33 Housing 46 Measuring bushing 59 Adjusting rod big
34 Screw plug 47 Measuring piston 60 Cylinder
35 Cradle 48 Cylinderical roller bearing 61 Control plate
36 Adjusting rod small 49 Coupling hub 62 Adjusting bushing big
37 Adjusting screw 50 Wire 63 Spring
38 Sealing nut 51 Screw plug 64 Orifice

2-5
2) STEERING PUMP

3 4

2
5

1
6

14
9
13 12 11 10
140WA2MP06

1 Drive shaft 6 High pressure side 11 Piston

2 Case 7 Control plate 12 Spring in piston
3 Spring 8 Port plate 13 Slipper pad
4 Stroke piston 9 Suction side 14 Swash plate
5 Control vavle 10 Cylinder

2-6
4. MAIN PUMP
1) FUNCTIONAL EXPLANATIONS
There is a priority between the individual controllers. The lowest priority has the LS controller with
override function (S2).
The controller with the highest priority is the power control with override (LE2). This protects the
diesel engine from overloading when the diesel engine is over-loaded.
(1) Basic function

Orifice
Stroke piston small

Orifice

Stroke piston big

140WA2MP07

The basic function of the controllers is as follows. The high pressure (red) serves for the rotary
group as a signal pressure. This pressure is send to a smaller stroke piston. This causes the
rotary group to swivel to Vgmax (large swivel angle). This stroke pressure is send across the port
plate to a bigger stroke piston. This is ensured by the larger piston area for the stroke pressure,
inside the stroke piston we have area ratio of (2:1). If the forces of the stroke side are bigger than
those of the high pressure side, then the unit swivel from Vgmax (large swivel angle) -> Vgmin
(small swivel angle). The swivel time can additionally be influenced by two orifice.
You can measure the pressure of the smaller stroke piston at G and the pressure from the bigger
stroke piston at M1.
As a special function, we also have a hydraulic Vgmin stop.

2-7
(2) Basic function controllers
The main pump has two controllers. A power controller (L) with electrical over-ride (E2) and a
load sensing controller (S) with electrical override (2).

S2

LE2

140WA2MP08

① Basic function power controller LE2

F1 F2 F3 F4 L4 L5 F5

140WA2MP09

We first consider the basic function without the override.

The piston F3 has three functions.
- When the control edge is closed, the unit keeps its swing angle.
- When the control edge connects red and orange. The unit swivel until to Vgmin.
- When the control edge connects orange and green. The unit swivel until to Vgmax.
Two forces or torques act on the control piston. The first torque (D5) is set constantly. It consists of
the spring force F5 and the lever arm L5. The second torque (D4) consists of the lever arm L4
and the force that is generated on the piston F4. F4 = (area x high pressure) If the torque of D4 is
greater than that of D5. The unit swivel to Vgmin. This reduce the angle lever arm L4 until the
torques are balanced again.
F4 X L4 = M = F5 X L5
Power override
The solenoid force F1 enables us to generate a new force that acts directly against the spring
force F5 and thus reduces the force F4 required.
We can say: Higher current = lower power setting

2-8
② Load sensing controller S2

F6 F11 F7 F8 F10

140WA2MP10

We first consider the basic function without the override.

The piston F7 has three functions.
- When the control edge is closed, the unit keeps its swivel angle.
- When the control edge connects red and orange. The unit swivel until to Vgmin.
- When the control edge connects orange and green. The unit swivel until to Vgmax.
With the load sensing controller, we consider the high pressure of the pump (F11) and the
external load pressure (F8). The control Δp is set via the spring force (F10).
We can say F11 = F8 + F10.
If F11 is greater than F8 + F10, the unit swivel to Vgmin until it balances again. The spring force
F8 is fixed. To change the Δp during the operation. We have the possi-bility to generate a new
force via the solenoid F6.
We can say: higher current = smaller Δp setting.

2-9
2) ADJUSTMENT
(1) Power controller

M/Nm
P theor. corner power
380 800 P-Q diagram
Pinfo

Horse power override by EPPRV (mA/bar)

Minfo 1 Individual power control
1 Pworking (hyperbolic regulator)
High pressure (bar)

Mworking 2 With load limiting control

PEco-mode via solenoid
MEco mode
3. Qmin setting
2 4. Qmax setting

3Q=20.00 l,min bei Ppr=50 bar Q=224.3 l,min bei Ppr=50 bar 4
50

0
0 220 l/min
Q
Flow (l/min)
140WA2MP11

Because the power controller can be overridden with a solenoid. It need the following three points
of information for the setting point.
Current, swivel angle of the pump and Δp pressure.
First we come to the swivel angle of the pump. Here is important that the unit stand on Vgman.
You can check this over the measuring port G and M1. You should see the high pressure on G
and no or a lower pressure than 1 (pressure on G) to 3 (pressure at M1). Than check, that you
don´t limited the Vg with the stroke limiter screw.
Current: You need the current from the diagram on the solenoid for the override function.
Pressure: You need the high pressure from the p-Q diagram on the measuring port G.
Example for the yellow line: pressure: 160 bar, current 600mA, Vg=145ccm
(q=145ccmX1600 l/min /1000=232 liter)

(2) Power controller override (load limiting control)

M/Nm
P theor. corner power
380 800
P-Q diagram
Horse power override by EPPRV (mA/bar)

Pinfo

Minfo 1 Individual power control

1 Pworking
(hyperbolic regulator)
2 With load limiting control
High pressure (bar)

Mworking

via solenoid
PEco-mode
MEco mode
2 3. Qmin setting
4. Qmax setting

Power override IX3 via ECU

3 4 (enging control unit)
Q=20.00 l,min bei Ppr=50 bar Q=224.3 l,min bei Ppr=50 bar

50
0
220 l/min
0
Q
Flow (l/min)
140WA2MP12

2-10
(3) Load sensing controller
35

30

25

20

15

10

0
0 200 400 600 800
140WA2MP13
Current in mA

Because the LS controller can be overridden with a solenoid. It need the following two pieces of
information for the setting point. Current and Δp pressure. You can get this information
individually from your HD Hyundai Construction Equipment dealer.
If you have this information, drive the current at the override to the desired value and set the
desired Δp using the control screw on the LS controller.
In the picture you see two examples.
You can give current to the controller with 200 mA and 25 bar Δp or 600 mA and 14 bar Δp. The
result would be the same.
The controller moves on the characteristic from the diagram.

2-11
5. STEERING PUMP
1) FUNCTIONAL DESCRIPTIOM
3 4

2
5

1
6

14
9
13 12 11 10
140WA2MP03

1 Drive shaft 6 High pressure side 11 Piston

2 Case 7 Control plate 12 Spring in piston
3 Spring 8 Port plate 13 Slipper pad
4 Stroke piston 9 Suction side 14 Swash plate
5 Control vavle 10 Cylinder

(1) Pump
Torque and rotational speed are applied to the drive shaft (1) by an engine. The drive shaft is
connected by splines to the cylinder (10) to set this in motion. With every revolution, the pistons
(11) in the cylinder bores execute one stroke whose magnitude depends on the setting of the
swash plate (14). The slipper pads (13) are held on and guided along the glide surface of the
swash plate by the spring in the piston (12). The swash plate setting during a rotation causes
each piston to move over the bottom and top dead centers and back to its initial position. Here,
hydraulic fluid is fed in and drained out through the two control slots in the control plate (7)
according to the stroke displacement. On the suction side (9) hydraulic fluid flows into the piston
chamber as the piston recedes. At the same time, on the high-pressure side (6) the fluid is
pushed out of the cylinder chamber into the hydraulic system by the pistons.
(2) Control
The swivel angle of the swash plate (14) is steplessly variable. Controlling the swivel angle of the
swash plate changes the piston stroke and therefore the displacement. The swivel angle is
changed hydraulically by means of the stroke piston (4). The swash plate is mounted for easy
motion in swivel bearings. When pressurized, the swash plate is held in balance by the swiveling
forces of the rotary group, which are generated by the eccentrically mounted swash plate and by
the control pressure. When depressurized, the spring (3) presses the swash plate to maximum
swivel angle. Increasing the swivel angle increases the displacement; reducing the angle results
in a corresponding reduction in displacement.

2-12
2) CONTROLLER (pressure controller with load sensing)

S0

DR

140WA2MP14

The pressure controller limits the maximum pressure at the pump outlet within the control range
of the variable pump. The variable pump only supplies as much hy-draulic fluid as is required by
the consumers. If the operating pressure exceeds the pressure setting at the pressure valve, the
valve opens the connection from P-chan-nel (high pressure) to A-channel (stroking pressure) and
the pump will regulate to a smaller displacement to reduce the control differential.
In addition to the pressure controller function, the load-sensing controller (S0) works as a flow
controller to regulate the pump displacement to match the consumer flow requirement.
A variable orifice is used to adjust the differential pressure upstream and down-stream of the
orifice. The flow controller is working like a pressure compensator to keep a constant delta p by
comparing the high pressure against the load-sensing (LS) pressure plus spring preload. If the
LS pressure plus spring preload exceeds the high pressure, the controller piston opens the
connection from A-channel (stroking pressure) to T-channel (tank/housing) and the pump
displacement will increase. If the high pressure exceeds the LS pressure plus spring preload, the
controller pis-ton opens the connection from P-channel (high pressure) to A-channel (stroking
pressure) and the pump displacement will decrease.

Basic position in depressurized state: Vg max

Vg × n × ηv
Flow qv= [ℓ/min]
1000

Vg - Displacement per revolution [cm3]

n - Rotatinal speed (rpm)
ηv - Volumetric efficiency

2-13
3) ADJUSTMENT OF PRESSURE CONTROLLER WITH LOAD SENSING

1 2/3 directional valve

2 Metering orifice/shut off valve
3 3 Load vavle
PHD2 4 M1easuring motor, flow measuring device

p
2
PHD1

1
140WA2MP15
S
X

Please note the mounting position of the controller and watch out for the notched letters:
D = Pressure controller
F = Flow controller

F-Regulator
Adjustment
L L1 D-Regulator D
B Locking torque
1.2 kgf m (8.9 lbf ft)
F

S 140WA2MP16

※ Special tool

For setting the controllers, we

recommend using a special tool
as you can see in the picture
below. With this tool deviations of
the values are prevented.

140WA2MP17

2-14
 ※ Tightening torque
6.1+1.0 kgf m (44.3+7.4 lbf ft) 1.2+0.5 kgf m (8.9+3.7 lbf ft)
slightly oiled

1.2+0.5 kgf m (8.9+3.7 lbf ft)

slightly oiled 140WA2MP18

(1) Adjustment of pressure controller (D)

Setting range until 250 bar
1. Turn adjusting screw of F-controller on block
2. Release the adjusting screw of D-controller
3. Close load valve
4. Tighten setting screw (1) of D-controller with lock nut (2) and 1.2+0.5 kgfᆞm torque until the
pressure to be adjusted is reached (one revolution + 59.5 bar).

DR

S0

1 2 140WA2MP19

1 Setting screw 2 Lock nut

※ Upon setting without a special tool the following must be kept in mind:
After setting the controller setting screw (AF4) the set value can show an increase of
approx. 7 bar due to tightening of the lock nut. The set values of the controller should
therefore be correspondingly lower. Since especially new controllers can change their
setting values in operation, due to settling of the springs, testing of the settings must be
repeated 2-3 times, if needed correct settings. Make sure, that the load valve and the and
the pressure control valve are unloaded. Setting of the pressure controller via the load
valve according to the performance diagram.

2-15
(2) Adjustment of delta p setting (F)
Setting range 14 – 35 bar
1. Release the adjusting screw of F-controller
2. Release X-channel
3. Adjust standby-pressure at setting screw (1) (one revolution = 12.3 bar) and secure the lock
nut (2) with a slotted screw driver (width 8.8 mm) with a torque of 1.2+0.5 kgfᆞm.

1 2

DR

S0

140WA2MP20

1 Setting screw 2 Lock nut

※ When settings are done without special tools, the following must be considered: After
setting of the FR setting screw (AF4) the set value can be increased by approx. 1.5 bar
through tightening of the lock nut. Therefore the set value of the FR controller should be
set a bit lower. Since especially new controllers can change their setting values in
operation, due to settling of the springs, testing of the settings must be repeated 2 to 3
times, if needed correct settings.

2-16
GROUP 2 MAIN CONTROL VALVE

1. OUTLINE

b8
b7 b6 b4
b5 b3
b2 b1

R1
B8 B7 B6 B5 B4 B3
B2 B1

P
A2 A1
A8 A7 A6 A5 A4 A3 MP

R2
LS1

Z a2 a1

S LS2
a5 a3
a7 a6 a4
140WA2MC01
a8

Mark Port name Mark Port name

P Pump port A7 Swing port (LH)
R1 Tank port (cooler) B7 Swing port (RH)
R2 Tank port A8 Option port
S Make up port B8 Option port
LS1 Load sensing port a1 Dozer down pilot port
LS2 Pressure switch b1 Dozer up pilot port
MP Plugged a2 2 pcs boom up pilot port (opt)
Z Power boost port b2 2 pcs boom down pilot port (opt)
A1 Dozer down port a3 Boom up pilot port
B1 Dozer up port b3 Boom down pilot port
A2 2 pcs boom up port (opt) a4 Arm out pilot port
B2 2 pcs boom down port (opt) b4 Arm in pilot port
A3 Boom up port a5 Bucket in pilot port
B3 Boom down port b5 Bucket out pilot port
A4 Arm out port a6 Travel pilot port (FW)
B4 Arm in port b6 Travel pilot port (RR)
A5 Bucket in port a7 Swing pilot port (LH)
B5 Bucket out port b7 Swing pilot port (RH)
A6 Travel port (FW) a8 Option pilot port
B6 Travel port (RR) b8 Option pilot port

2-17
2. STRUCTURE
1) INLET SECTION

140WA2MC02

241 Pressure relief valve 543 Screw 721 Check valve

482 Flow valve 681 Pressure relief valve 722 Check valve

2) BOOM SECTION

140WA2MC03

202 Cover assy 241 Pressure relief valve 781 Spool assy
205 Spring 361 Spool assy

2-18
3) ARM SECTION

140WA2MC04

205 Spring 361 Spool assy 781 Spool assy

241 Pressure relief valve 402 Cover assy

4) BUCKET SECTION

140WA2MC05

201 Spool assy 205 Spring 361 Spool assy

202 Cover assy 241 Pressure relief valve 782 Spool assy

2-19
5) TRAVEL SECTION

140WA2MC06

201 Spool assy 361 Spool assy 441 Pressure relief valve
206 Spring 402 Cover assy 782 Spool assy

6) SWING SECTION

140WA2MC07

205 Spring 402 Cover assy 795 Spool assy

361 Spool assy 581 Relief valve
383 Spool assy 791 Spool assy

2-20
7) OPTION SECTION

140WA2MC08

202 Spool assy 225 Spool assy 361 Spool assy

205 Spring 243 Pressure relief valve 781 Spool assy

8) 2 PIECE BOOM SECTION

140WA2MC09

212 Pressure relief valve 225 Spool assy 242 Cover kit
220 Check vavle 240 Cover kit

2-21
9) DOZER (OUTRIGGER) SECTION

140WA2MC10

211 Pressure relief valve 225 Spool assy 242 Cover kit
220 Check valve 240 Cover kit

2-22
 OPTION1 SWING TRAVEL BUCKET ARM BOOM 2 PIECE OUTRIGGER
3. HYDRAULIC CIRCUIT

b8 B8 A8 b7 B7 A7 b6 B6 A6 b5 B5 A5 b4 B4 A4 b3 B3 A3 R1 b2 B2 A2 b1 B1 A1

2-23
T A T T B A T
B

a2 a1
a8 a7 L1 a/b a6 a5 a4 a3 Z LS2 LS1 S R2 P MP

140WA2MC11
4. FUNCTION
1) INLET SECTION
(1) Structure

1
2

3
9

6 5

140WA2MC20

R1 1 Pump channel (P)

2 2 stage LS pressure relief valve
3 Tank channel
4 Tank port (R1, cooler)
5 Tank port (R2)
6 LS channel
7 Primary relief valve
8 Unloading valve
9 LS drain valve

Z LS2 LS1 S R2 P MP
140WA2MC21

2-24
 (2) 2 stage LS relief valve
The pressure valve type is a direct operated pressure relief valve for the installation in block
designs. It is used to limit a system pressure. The system pressure can be set steplessly via the
adjustment element.
1.0 kgf m (7.4 lbf ft) 1.0 kgf m (7.4 lbf ft)

3
14 3 16
2
1

1
2

140WA2MC22

※ For the case of unintentional adjustment during assembly process, we would recommend to
mark the positions by sealing wax.

① Pressure relief function

In the initial position the valve is closed. The pressure in the main port 1 acts on the spring plate
(4) via pilot line (1) and poppet (14). If the pressure in the main port 1 rises above the value set
at the comparisson spring (16), poppet (14) opens and the pressure fluid flows in to the main
port 2.

② Pressure connect function

When connecting the external port 3 with pilot pressure, piston (3) will be pressurised. The
pretension of the spring and the maximum adjusted system pressure are increasing. A
pressureinsation at the external port 3 affects the pressure at the main port 1. Ratio the following
pages.

2-25
2) COMMON SECTION
(1) Neutral position

b BA

LS
P
T

a 140WA2MC23

In neutral position, no connection between pump an consumer and also no connection between
consumer an tank channel.
Pressure compensator is completely closed, no movements possible.

(2) Single mode/highest load

b BA
A B

LS
P
T

a 140WA2MC24

Pilot pressure on A-side opens the spool and connects pump to consumer A.
Compensator is completely open, because of single mode or highest system load of the section.
In parallel the spool opens consumer B to tank, based on defined opening area.

2-26
(3) Parallel mode/ lower load
b B A

A B

LS
P
T

a 140WA2MC25

Pilot pressure on A-side opens the spool and connects pump to consumer A.
The compensator gets the signal of highest system load to the spring chamber and throttles
automatically the difference between pump pressure and specific consumer load.

2-27
3) BOOM SECTION
(1) Structure

A3 B3

140WA2MC26

1 Pump channel 6 Pressure compensator 10 Tie rod holes

2 Tank channel 7 Pilot cover 11 Stroke limiter
3 Port A3 8 Secondary relief valves 12 LS-line
4 Port B3 with make-up functionality
5 Main spool with regeneration 9 Load holding valves

(2) Neutral position

A3 B3
b3 B3 A3

LS
P
T

a3 140WA2MC27

Neutral position of boom spool, port A3 is connected to tank by a small notch. All other
connections of the spool are closed.

2-28
(3) Boom up position
A3 B3
b3 B3 A3

LS
P
T

a3 140WA2MC28

When the pilot pressure is led to the port a3, the oil from the pump flows to the cylinder port A3
and oil from the cylinder flows into the tank through the cylinder port B3.

(4) Boom down position

A3 B3
b3 B3 A3

LS
P
T

a3 140WA2MC29

When the pilot pressure is led to the port b3, the oil from the pump flows to the cylinder port B3
and oil from the cylinder flows into the tank through the cylinder port A3.

2-29
(5) Boom regeneration spool

A3 B3

140WA2MC30

1 Pump channel 6 Pressure compensator 10 Tie rod holes

2 Tank channel 7 Pilot cover 11 Stroke limiter
3 Port A3 8 Secondary relief valves 12 LS-line
4 Port B3 with make-up functionality
5 Main spool with regeneration 9 Load holding valves

Pump is connected with B3 port. A3 port to tank. Internally connected to the poppet, as well as
pump pressure. If pressure on A3 port is higher than on B3 port, the poppet opens and
regeneration of flow starts. Flow depends on delta-p between A3 and B3.

2-30
4) ARM SECTION
(1) Structure

A4 B4

140WA2MC31

1 Pump channel 6 Pressure compensator 11 Stroke limiter

2 Tank channel 7 Pilot cover 12 LS-line
3 Port A4 8 Secondary relief valves
4 Port B4 with make-up functionality
5 Main spool with Brake and 9 Load holding valves
regeneration functionality 10 Tie rod holes

(2) Neutral position

A4 B4
b4 B4 A4

LS
P
T

a4 140WA2MC32

Neutral position of arm spool, all connections of the spool are closed and the A4 and B4 ports are
not connected to the pump nor tank.

2-31
(3) Arm out position
A4 B4
b4 B4 A4

LS
P
T

a4 140WA2MC33

When the pilot pressure is led to the port b4 the oil from the pump flows to the cylinder port B4
and oil from the cylinder flows into the tank through the cylinder port A4.

(4) Arm in position

A4 B4
b4 B4 A4

LS
P
T

a4 140WA2MC34

When the pilot pressure is led to the port a4, the oil from the pump flows to the cylinder port A4
and oil from the cylinder flows into the tank through the cylinder port B4.

2-32
(5) Brake and regeneration spool

A4 B4

7
3 2 4

Regeneration Brake
valve 1 Regeneration valve
2 Logic brake valve
3 Pilot spool brake valve
Pressure
compensator 4 Spring chamber brake valve

140WA2MC35

Pump flow is connected over compensator and load holding valve to the port A4.
Regeneration valve is closed, because pressure on port A4 is bigger than on port B4.
Port A4 is also connected to pilot spool brake valve.
Spring chamber of logic valve is released to tank pressure. Based on area ratio of the pilot spool
and the logic brake valve, the port A4 pressure has to reach a pressure level of 120 bar.
Regeneration function is not active/closed, because pressure on port A4 is bigger than on port B4.

2-33
5) BUCKET SECTION
(1) Structure

A5 B5

140WA2MC36

1 Pump channel 6 Pressure compensator 10 Tie rod holes

2 Tank channel 7 Pilot cover 11 Stroke limiter
3 Port A5 8 Secondary relief valves 12 LS-line
4 Port B5 with make-up functionality
5 Main spool 9 Load holding valves

(2) Neutral position

A5 B5
b5 B5 A5

LS
P
T

a5 140WA2MC37

Neutral position of bucket spool, all connections of the spool are closed and the A5 and B5 ports
are not connected to the pump nor tank.

2-34
(3) Bucket in position
A5 B5
b5 B5 A5

LS
P
T

a5
140WA2MC38

When the pilot pressure is led to the port a5, the oil from the pump flows to the cylinder port A5
and oil from the cylinder flows into the tank through the cylinder port B5.

(4) Bucket out position

A5 B5
b5 B5 A5

LS
P
T

a5
140WA2MC39

When the pilot pressure is led to the port b5, the oil from the pump flows to the cylinder port B5
and oil from the cylinder flows into the tank through the cylinder port A5.

2-35
6) TRAVEL SECTION
(1) Structure
Both sides of the Travel spool B6->T and also A6->T are connected in neutral to tank.
A6 B6

140WA2MC40

1 Pump channel 5 Main spool 9 Load holding valves

2 Tank channel 6 Pressure compensator 10 Tie rod holes
3 Port A6 7 Pilot cover 11 Stroke limiter
4 Port B6 8 Secondary relief valves 12 LS-line

(2) Travel backward position

A6 B6

140WA2MC41

When the pilot pressure is led to the port a6, the oil from the pump flows to the port A6 and oil
from the motor flows into the tank through the port B6.

2-36
(3) Travel forward position

A6 B6

140WA2MC42

When the pilot pressure is led to the port b6, the oil from the pump flows to the port B6 and oil
from the motor flows into the tank through the port A6.

2-37
7) SWING SECTION
(1) Structure
A7 B7
1 Pump channel
2 Tank channel
3 Port A7
4 Port B7
5 Main spool
6 Hollow Pressure compensator
7 Pilot cover
8 DTS cartridge
9 Load holding valves
10 Tie rod holes
11 Stroke limiter
12 LS-line
13 LS pressure reducing valve
140WA2MC43
14 LS copy valve

A7 B7 1 Pump channel
2 Tank channel
3 Port A7
4 Port B7
5 LS pressure reducing valve
6 Hollow pressure compensator
7 Pilot cover
8 DTS cartridge
9 LS copy valve
10 Tie rod holes
11 Stroke limiter
12 LS-line

140WA2MC44

A7 B7 1 Pump channel
2 Tank channel
3 Port A7
4 Port B7
5 Main spool
6 Hollow Pressure compensator
7 Pilot cover
8 LS-line
9 Load holding valves
10 Tie rod holes

140WA2MC45

2-38
(2) Neutral position
A7 B7
b7 B7 A7

a7 L1 a7/b7
140WA2MC46

Neutral position of swing spool, all connections of the spool are closed and the A7 and B7 ports
are not connected to the pump nor tank.

(3) Swing right position

A7 B7
b7 B7 A7

a7 L1 a7/b7
140WA2MC47

When the pilot pressure is led to the port a7, the oil from the pump flows to the port A7 and oil
from the motor flows into the tank through the port B7.

2-39
(4) Swing left
A7 B7
b7 B7 A7

a7 L1 a7/b7

140WA2MC48

When the pilot pressure is led to the port b7, the oil from the pump flows to the port B7 and oil
from the motor flows into the tank through the port A7.

(5) LS neutral position

A7 B7

b7 B7 A7

a7 L1 a7/b7

140WA2MC49

The pump channel is always connected to the compensator. If pump pressure is higher than LS +
spring setting of the LS-compensator, the LS compensator will be closed.
The LS channel will be in parallel released to tank and also by the copy valve to the spring
chamber of the compensator.
This secures no movement during neutral position of the spool.
2-40
(6) LS highest load
A7 B7

b7 B7 A7

a7 L1 a7/b7

140WA2MC50

Pilot signal on port A7 opens pump -> port A7 and also port B7 -> tank channel.
LS signal is spool internally connected to spring chamber of the compensator.
LS signal + spring force setting defines the delta p over main spool.
-> This combination leads to precise flow controllability.
The DTS drains the LS signal, in relation to the pilot signal, to the tank channel. The reduced LS
pressure is connected to the compensator, which leads to “torque control” of the consumer.

2-41
(7) LS lowest consumer load

A7 B7

b7 B7 A7

a7 LS a7/b7

140WA2MC51

Against LUDV functionality, the LS section is not affected by parallel movements, as long as the
system is able to build up the required pump pressure.
We call it “semi-priority” for LS consumers.

2-42
8) OPTION SECTION
(1) Structure
EPPR (position 8) should not be engaged with current, without connected hydraulic oil.
-> This avoids air injection into the PPRV.

PPRV

140WA2MC52

1 Pump channel 6 Pressure compensator 9 Load holding valves

2 Tank channel 7 Pilot cover 10 Tie rod holes
3 Port A8 8 Electro-proportional 11 Stroke limiter
4 Port B8 secondary relief valves 12 LS-line
5 Main spool with make-up functionality

(2) Neutral position

A8 B8
b8 B8 A8

LS
P
T

a8
140WA2MC53

Neutral position of option spool, all connections of the spool are closed and the A8 and B8 ports
are not connected to the pump nor tank.

2-43
(3) A8 side piloted

A8 B8 b8 B8 A8

LS
P
T

a8
140WA2MC54

When the pilot pressure is led to the port a8, the oil from the pump flows to the port A8 and oil
from the cylinder flows into the tank through the port B8.

(4) B8 side piloted

A8 B8 b8 B8 A8

LS
P
T

a8
140WA2MC55

When the pilot pressure is led to the port b8, the oil from the pump flows to the port B8 and oil
from the cylinder flows into the tank through the port A8.

2-44
(5) PPRV control information

Tool : Spanner 30
Tightening torque : 10.2±1.0 kgf.m (73.8±7.4 lbf.ft) 140WA2MC56

Flow - pressure curve p=f

Delta p (pA-pT) Main flow (l/min)

Main flow (l/min)

Delta p (bar)

Current (A) 140WA2MC57

2-45
 ᆞ Adjustment

For adjusting : L-wrench 4 mm

Tool : Spanner 13 mm
Tightening torque : 0.41±0.1 kgf.m (3.0±0.07 lbf.ft) 140WA2MC58

- Release the counter nut (green)

- Turn the positioning screw smoothly (brown)
- Fix the counter nut again (green)

※ In general the adjustment of the pressure settings will be done in our production line.
Afterwards we will seal the adjustment with sealing wax to avoid re-adjustment in the field.

2-46
9) 2-PIECE BOOM
(1) Structure

140WA2MC59

1 Pump channel 6 Pressure compensator 10 Tie rod holes

2 Tank channel 7 Pilot cover 11 Stroke limiter
3 Consumer port A 8 Secondary relief valves 12 LS-line
4 Consumer port B with make-up functionality 13 Snubber
5 Main spool 9 Load holding valves
(2) Neutral position
A2 B2
b2 B2 A2

P
LS

T
T A T
B

a2
140WA2MC60

The spool is in neutral position, pump is in low pressure stand-by. The A2 and B2 ports are not
connected to the pumps nor the tank.

2-47
(3) Boom up position
A2 B2
b2 B2 A2

P
LS

T
T T
B A

a2
140WA2MC61

When the pilot pressure is led to the port a2, the oil from the pump flows to the cylinder port A2
and oil from the cylinder flows into the tank through cylinder port B2.

(4) Boom down position

A2 B2
b2 B2 A2

P
LS

T
T T
B A

a2
140WA2MC62

When the pilot pressure is led to the port b2, the oil from the pump flows to the cylinder port B2
and oil from the cylinder flows into the tank through the cylinder port A2.

2-48
10) OUTRIGGER SECTION
(1) Neutral psition
A1 B1
b1 B1 A1

P
LS

T
T A T
B

a1
140WA2MC63

The spool is in neutral position, pump is in low pressure stand-by. The A1 and B1 ports are not
connected to the pumps nor the tank.

(2) A1 side piloted

A1 B1
b1 B1 A1

P
LS

T
T T
B A

a1
140WA2MC64

When the pilot pressure is led to the port a1, the oil from the pump flows to the cylinder port A1
and oil from the cylinder flows into the tank through cylinder port B1.

2-49
(3) B side piloted

A1 B1
b1 B1 A1

P
LS

T
T T
B A

a1
140WA2MC65

When the pilot pressure is led to B1 side, the oil from the pump flows to the cylinder port B1and oil
from the cylinder flows into the tank through the cylinder port A1.

2-50
GROUP 3 SWING DEVICE

1. STRUCTURE

B G A
MB(MA)
MBA Brake bleed screw

X
Mechanical brake release

X 1 140WA2SM01

Port Port name Port size

A Main port 1-1/16-12 UNF
B Main port 1-1/16-12 UNF
G Make up port 7/8-14 UNF
MA Gauge port 3/4-16 UNF
MB Gauge port 3/4-16 UNF

MAB MBA Gauge port 7/16-20 UNF

X Brake release port 9/16-18 UNF
MB MA 1 Drain port 7/8-14 UNF

B G A
Hydraulic circuit

2-51
2. PART LIST
1) SUPPORT BEARING ASSY

140WA2SM02

1005 Bearing housing 1205 Taper bearing 9100 Full motor seal kit
1105 Pinion shaft 1305 Taper bearing

2) BRAKE ASSY

140WA2SM03

2005 Brake housing 2305 Brake piston 2950 Screw

2010 Screw 2425 Brake disk seal kit 9200 Brake repair kit
2040 Washer spring 2550 Lock plate 9210 Brake disc repair kit
2205 Brake shaft 2555 Screw 9225 Brake cover repair kit
2210 Brake shaft seal kit 2575 Plug

2-52
 3) CYLINDER BLOCK ASSY

140WA2SM04

3010 Piston repair kit 9300 Piston insite kit 9350 Open motor repair kit
3505 Cam 9305 Piston ring repair kit

4) VALVE COVER ASSY

140WA2SM05

4005 Valve housing 4115 Distribute seal kit 9400 Valve repair kit
4070 Screw 4950 Screw 9420 Compression spring kit
4105 Valve block 4960 Plug

2-53
5) VMR VALVE ASSY

140WA2SM06

5110 O-ring 6505 O-ring 9661 Relief valve seal kit

5115 O-ring 6611 Screw
5125 Conte joint 6612 Relief valve

2-54
3. GENERAL DESCRIPTION
This hydraulic motor is designed to swing the upper structure of the excavator and changes the
hydraulic pressure oil supplied from the pump to the rotary motion.
This is the radial piston type for low speed-high torque and section is as blow.

Swing valve block assy

Bearing support assy

Hydrobase assy Valving cover assy Brake saay

140WA2SM10

This hydraulic motor consists of the five major subassembly such as bearing support assembly,
hydrobase assembly, valving cover assembly, brake assembly and swing valve block assembly (VMR
valve assembly).

2-55
The hydraulic pressure oil flows into hydrobase through the valving cover assembly and the
hydraulic energy changes to mechanical energy by the hydrobase. As a result, the upper structure
is rotated through the pinion gear of the bearing support.
When the hydraulic oil is supplied to the A port (red) and this pressure oil flows through valving
plate (fixed part, not rotating) and cylinder block (3005,rotating part, connect to the the pinion shaft
by inside spline) and push red area of the cam (3505) through the piston and cylinder roller. Thus
rotating torque is occurred.
(The upper structure starts rotating)

3505

3005

4105

140WA2SM11

The other way, the blue port oil flows into the piston through the cylinder roller and flows into B port
through the cylinder block and valving plate. Incase the upper structure stops from rotating, the
resist rotating torque generates due to the throttle effect of the orifice by the slope of the blue area
of the cam, then the upper structure stops. (hydrostatic brake function)
The green chamber is filled with oil during the operation, the internal leakage of the motor (leakage
of the mechanical contact part of the 3005 and 4105) and leakage of between piston and cylinder
block) flows in to green chamber and drains to hydraulic tank without resistance surely. The sealing
status of the motor can be checked by measuring this drain oil.
The internal leakage of the motor does not exceed 0.14 lpm at the drain port when the supply oil
quantity is 30 lpm.

2-56
4) BRAKE SYSTEM
(1) Control valve swing brake system
This is the brake system to stop the swing motion of the excavator during operation.
In this system, the hydraulic circuit is throttled by the swing control valve, and the resistance
created by this throttling works as a brake force to slow down the swing motion.

Work Deceleration Stop

A B A B A B

MCV MCV MCV

MCV A, B opened MCV A, B throttled MCV A, B closed

2-48(1)

(2) Mechanical swing parking brake system

This is function as a parking brake only when the swing control lever and arm in control lever are
not operated.

① Brake assembly
Circumferential rotation of separate plate
(2435) is constrained by the groove
2305 2040
located at brake housing (2005). When
housing is pressed down by washer
spring (2040) through friction plate
(2425), separate plate (2435) and brake 3000
piston (2305), friction force occurs
2425
between friction plate and separate plate.
2435
Friction force constrains motion of
Groove
cylinder block (3000). When hydraulic
force exceeds spring force, brake is
released.
140WA2SM12

2005 Brake housing 2425 Friction plate

2040 Washer spring 2435 Separate plate
2305 Brake piston 3000 Cylinder block

2-57
② Operating principle
a. When any of the swing or arm in function is operated, the swing brake solenoid valve (5) is
shifted to the swing position, so brake pump charged oil goes to the chamber G through port X.
This pressure is applied to move the parking piston (2305) to the upward against the force of
the washer spring (2040). Thus, it releases the brake force.
b. Stop operation and a few second has been elapsed, the swing brake solenoid valve (5) is
shifted to the swing parking position and swing brake works.
c. There is time delay for swing parking as below (single operation).
- Swing : 5 sec, arm in : 1 sec, boom up : 2 sec, travel : 3 sec.

2305 2040

4-cartridge valve

A
P

1
5
T

140WA2SM13
1 Brake pump 2040 Washer spring
5 Swing brake solenoid valve 2305 Brake piston

2-58
③ Manual override function
When the swing parking solenoid valve or related electric system is malfunction, the swing
parking brake is not released even if the swing or arm in lever is operated.
To release the swing parking brake, the manual override function is needed.

※ Manual override solenoid valve

a. Use hand only to turn the control knob Control knob
(do not use a tool).
Parking work Parking release
b. Parking brake release
Turn the control knob to counterclockwi-
se fully (about 2.5 mm)
c. Parking brake work
Turn the control knob to clockwise fully.
※ Be careful not damage the control
knob by using a tool or tightening forci-
bly.
It can cause malfunction of the soleno-
id valve.
Swing parking solenoid valve
160A2SM11

2-59
 GROUP 4 TRAVEL MOTOR

1. CONSTRUCTION
Travel motor consists motor unit and regulator and counterbalance valve.
ᆞHigh speed (standard)

U T X2 X2
Motor unit M2
M2
M3
M3
Regulator Gext
MB(MA)

X Gext B A

S
Counterbalance valve
T G X G X
VIEW Y

MA MB

VIEW X

T 140WA2TR01

T
GU Port Port name Port size
M2 A, B Main port SAE 1"
X2 G Plugged M14×1.5-12
qmax <-> qmin
M1 Gauge port M14×1.5-12
M3
X X Pilot pressure port M14×1.5-12
MB MA
X2 Pilot pressure port M14×1.5-12
T Drain port PF 1/2-16
U Flushing port PF 1/2-16
S Make up port M27×2.0-14
MA, MB Gauge port M18×1.5-12
Gext.
M2, M3 Gauge port M10×1.0-8
B(Fw)
S
A(Bw) Gext Brake release port M12×1.5-12.5
Hydraulic circuit

2-60
ᆞLow speed (option)

Motor unit U T M1
M1
Regulator
Gext
MB(MA)

X Gext B A

S
Counterbalance valve G X
T G X
VIEW Y

MA MB

VIEW X

T
140WA2TR02
T
GU Port Port name Port size
A, B Main port SAE 1"
G Plugged M14×1.5-12
qmax <-> qmin M1
M1 Gauge port M14×1.5-12
X X Pilot pressure port M14×1.5-12
MB MA
T Drain port PF 1/2-16
U Flushing port PF 1/2-16
S Make up port M27×2.0-14
MA, MB Gauge port M18×1.5-12
Gext Brake release port M12×1.5-12.5
Gext.

B(Fw) S A(Bw)

Hydraulic circuit

2-61
 1) PARTS LIST (1/3)
(1) High speed

MOTOR ASSY ITEM 1

1 Motor housing assy

2 Rotary kit

ITEM 2

2-2-12
140WA2TR10

1-1 Housing 1-11 Sealing nut 2-3 Shim

1-2 Lock screw 1-12 Threaded pin 2-6 Backup plate
1-3 Lock screw 2-1 Hydraulic rotary section 2-7 Retainer ring
1-4 Motor seal kit 2-2 Drive shaft 2-10 Roller bearing
1-10 Threaded pin 2-2-12 Screw 2-11 Roller bearing

2-62
 (2) Low speed

MOTOR ASSY ITEM 1

1 Motor housing assy

2 Rotary kit

ITEM 2

2-2-12
140WA2T11

1-1 Housing 1-11 Sealing nut 2-6 Backup plate

1-2 Lock screw 2-1 Hydraulic rotary section 2-7 Retainer ring
1-3 Lock screw 2-2 Drive shaft 2-10 Roller bearing
1-4 Motor seal kit 2-2-12 Screw 2-11 Roller bearing
1-10 Threaded pin 2-3 Shim

2-63
PARTS LIST (2/3)
(1) High speed

MOTOR ASSY

3 Port plate assy

4 Control unit

140WA2TR12

3-1 Port plate 3-12 Socket screw 4-9 Pressure spring

3-2 Positioning piston 3-13 Cylinder pin 4-14 O-ring
3-3 Positioning trunnion 3-14 Locking screw 4-15 Socket screw
3-4 Threaded pin 3-50 Relief valve 4-16 Locking screw
3-6 Piston ring 4-1 Control housing 4-17 Retainer ring
3-7 Bushing 4-2 Control bushing 4-19 Thread pin
3-8 Socket screw 4-3 Control piston 4-20 Cylinder pin
3-9 O-ring 4-4 Adjust bushing 4-21 Seal lock nut
3-10 Check valve 4-5 Spring collar 4-22 Break pin
3-11 Socket screw 4-7 Pressure spring 4-29 Retainer disc

2-64
 (2) Low speed

MOTOR ASSY

3 Port plate assy

4 Control unit

140WA2TR13

3-1 Port plate 3-14 Locking screw 4-9 Pressure spring

3-2 Positioning piston 3-29 Plug 4-14 O-ring
3-3 Positioning trunnion 3-33 Lock screw 4-15 Socket screw
3-4 Threaded pin 3-43 Stop bushing 4-16 Locking screw
3-6 Piston ring 3-50 Relief valve 4-17 Retainer ring
3-8 Socket screw 4-1 Control housing 4-19 Thread pin
3-9 O-ring 4-2 Control bushing 4-20 Cylinder pin
3-10 Check valve 4-3 Control piston 4-21 Seal lock nut
3-11 Socket screw 4-4 Adjust bushing 4-22 Break pin
3-12 Socket screw 4-5 Spring collar 4-29 Retainer disc
3-13 Cylinder pin 4-7 Pressure spring

2-65
 PARTS LIST (3/3)
(1) High speed
MOTOR ASSY

5 Hydraulic stroke limiter

7 Motion control valve assy

140WA2TR14

5-1 Limiter housing 5-11 Orifice 7-11 Locking screw

5-2 Piston 5-12 O-ring 7-20 Locking screw
5-3 Control piston 5-13 Shim 7-21 Socket screw
5-4 Pressure spring 5-14 Break pin 7-22 Plug
5-5 Lock screw 7-1 Valve 7-23 O-ring
5-7 Socket screw 7-2 Shuttle valve 7-24 O-ring
5-8 O-ring 7-3 Brake piston assy 7-25 O-ring
5-9 Lock screw 7-6 Housing 7-27 Locking screw
5-10 Lock screw 7-10 Locking screw 7-28 Break pin
2-66
 (2) Low speed
MOTOR ASSY

5 Hydraulic stroke limiter

7 Motion control valve assy

140WA2TR15

5-1 Cover 7-10 Locking screw 7-24 O-ring

5-3 Throttle screw 7-11 Locking screw 7-25 O-ring
7-1 Valve 7-20 Locking screw 7-27 Locking screw
7-2 Shuttle valve 7-21 Socket screw 7-28 Break pin
7-3 Brake piston assy 7-22 Plug
7-6 Housing 7-23 O-ring

2-67
2. FUNCTION

Port plate

Motor unit

Counterbalance valve
140WA2TR05

1) VARIABLE DISPLACEMENT MOTOR (with integrated counterbalance valve)

The variable displacement motor has a rotary group in bent axis design.
The torque is generated directly at the drive shaft.
The cylinder barrel is driven by a tapered piston arrangement.
The change of displacement is generated by the control lens via positioning piston. The control
lens slides on a circular shaped surface.
In case of constant pump flow volume and high pressure
- The output speed is increased at smaller swivel angle, the torque is reduced
- The torque rises at swivel angle increase, the output speed is decreased
The max swivel angle is 25°, the min swivel angle is 0°.
The variable displacement motor with integrated counterbalance valve is designed to be operated
in open loop.
※ Min and max displacement are limited by a stop screw. Stepless adjustment to various higher
values is possible.
Reduction to smaller displacement may result in overspeeding the motor.
2) PORT PLATE
With high pressure dependent control HA1, mounted counterbalance valve, integrated secondary
pressure relief valves, plugged gauge and boosting ports, service ports to the rear.

2-68
 Port plate

Motor unit

Counterbalance valve 140WA2TR05

3) HIGH PRESSURE DEPENDENT CONTROL

The displacement is-dependent on operating pressure - automatically adjusted. Upon reaching
the operating pressure set at the control valve - internally measured at A or B - the motor swivels
from Vgmin to Vgmax until output torque = load torque. For values lower than the adjusted one the
motor keeps min swivel angle. The necessary positioning energy is taken from the respective high
pressure side via shuttle valve.
Swivelling results in a change of the displacement.
Swivel time is controlled by an orifice installed in the cover of the large positioning piston side.
4) COUNTERBALANCE VALVE
Mounted at the rear of the port plate.
Incase of downhill traveling or deceleration of the machine a counterbalance valve avoids
overspeeding and cavitation of hydraulic motor.
5) FUNCTION AS TO CIRCUIT DIAGRAM
Check valves in the inlet line A and B for by passing of the counterbalance valve.
At traveling forward the return oil flow is controlled by a counterbalance spool. At drop in inlet
pressure the counterbalance spool throttles the return oil flow. The motor is locked. The oil
behind the spool is led to the low pressure side via an additional check valve. Same function for
traveling forward and backward.
Braking means for the motor that
- At reduced or zero inlet flow the counterbalance spool reaches a modulating position or a neutral
position caused by spring force
- The high pressure oil (at outlet side of the motor) is returned to the low pressure side (at inlet
side) of the motor via crossover relief valves.
As the control pressure for regulation of the HA control via the integrated shuttle valve is no longer
available, the motor with HA control and counterbalance valve will swivel to its minimum
displacement during deceleration.
In addition, an external boost flow/pressure can be applied at port S for preventing cavitation.
※ counterbalance valves do not replace the service and parking brake.
2-69
GROUP 5 RCV LEVER

1. STRUCTURE
The casing has the oil inlet port P (primary pressure) and the oil outlet port T (tank). In addition the
secondary pressure is taken out through ports 1, 2, 3 and 4 provided at the bottom face.
※ Refer to the parts manual for the types of the RCV lever.

1) TYPE M25
LH RH
8 6 5 5 6 8
7 7

F
N
R
9 9

TYPE M26
Switches
Type No. LH RH
27 19 5 Rotating-CW 2-way clamp
Simultaneous Single
operation operation 6 Rotating-CCW 2-way release
M25 7 One touch decel Quick coupler
8 Ram lock Horn
9 Power max FNR switch

P T

A A
1 3 2 4
Hydraulic circuit

Pilot ports

Port LH RH Port size

4 P Pilot oil inlet port Pilot oil inlet port
2 3 P 1 T Pilot oil return port Pilot oil return port
T T
1 Left swing port Bucket out port
1 P 3 2 PF 3/8
2 Arm out port Boom up port
4
3 Right swing port Bucket in port
LH RH
4 Arm in port Boom down port
VIEW A-A
140WA2RL01A

2-70
2) TYPE M26

LH RH
8 6 5 5 6 8
7 7

F
N
R
9 9

TYPE M26

Switches

25 19 Type No. LH RH
Simultaneous Single 5 Rotating-CW 2-way clamp
operation operation
6 Rotating-CCW 2-way release
M26 7 One touch decel Quick coupler
8 Ram lock Horn
9 Power max FNR switch

P T

A A
1 3 2 4
Hydraulic circuit

Pilot ports

Port LH RH Port size

4 2
T P Pilot oil inlet port Pilot oil inlet port
P
1 3 T Pilot oil return port Pilot oil return port
FR
FR 3 1
P 1 Left swing port Bucket out port
T PF 3/8
2 4
2 Arm out port Boom up port

LH
3 Right swing port Bucket in port
RH
VIEW A-A 4 Arm in port Boom down port

140WA2RL02A

2-71
3) CROSS SECTION

No. No. Port

15-1 P 1 Case
LH 15-2 2, 4 2 Plug
15-3 1, 3, 7 3 Bushing
15-1 P 4-1 Spool
RH 15-2 1, 2, 3, 4 4-2 Shim
15-3 T 4-3 Spring
14-5 4-4 Spring seat
5 Spring
6-1 Plug
6-2 Push rod
14 6-3 O-ring
12
6-4 Rod seal
9
10 7 Spacer
8 Boot
14-1 9 Spacer
11
10 Joint Assy
6-2 11 Swash plate
6-4 12 Adjusting nut
8
7
13 Bushing
13 6-1 14-1 Boot
6-3 14-2 Spring pin
4-4 14-3 Housing
5
14-4 Housing
4-3
14-3 14-4 4-2 14-5 Handle
3 4-1 15-1 Filter
2 15-2 Connector
1 15-3 Connector
15-1
25-3 15-2
140WA2RL06

Item numbers are based on the type M25.

The construction of the pilot valve is shown in the attached cross section drawing. The casing has
vertical holes in which reducing valves are assembled.
The pressure reducing section is composed of the spool (4-1), spring (4-3) for setting secondary
pressure, return spring (5), spring seat (4-4) and shim (4-2). The spring for setting the secondary
pressure has been generally so preset that the secondary pressure is 5 to 20.5 kgf/cm2 (depending on
the type). The spool is pushed against the push rod (6-2) by the return spring.
When the push rod is pushed down by tilting the handle, the spring seat comes down simultaneously
and changes setting of the secondary pressure spring.

2-72
2. FUNCTIONS
1) FUNDAMENTAL FUNCTIONS
The pilot valve is a valve that controls the spool stroke, direction, etc of a main control valve. This
function is carried out by providing the spring at one end of the main control valve spool and apply-
ing the output pressure (secondary pressure) of the pilot valve to the other end.
For this function to be carried out satisfactorily, the pilot valve is composed of the following ele-
ments.
(1) Inlet port (P) where oil is supplied from hydraulic pump.
(2) Output ports (1, 2, 3 & 4) to apply pressure supplied from inlet port to ends of control valve spools.
(3) Tank port (T) necessary to control the above output pressure.
(4) Spool to connect output port to inlet port or tank port.
(5) Mechanical means to control output pressure, including springs that work on the above spools.
2) FUNCTIONS OF MAJOR SECTIONS
Item numbers are based on the type M25.
The functions of the spool (4-1) are to receive the supply oil pressure from the hydraulic pump at its
port P, and to change over oil paths to determine whether the pressure oil of port P is led to output
ports 1, 2, 3 & 4 or the output port pressure oil to tank port T.
The spring (4-3) works on this spool to determine the output pressure.
The change the deflection of this spring, the push rod (6-2) is inserted and can slide in the plug
(6-1).
For the purpose of changing the displacement of the push rod through the swash plate (11) and
adjusting nut (12) are provided the handle (14-5) that can be tilted in any direction around the ful-
crum of the universal joint (10) center.
The spring (5) works on the case (1) and spring seat (4-4) and tries to return the push rod (6-2) to
the zero-displacement position irrespective of the output pressure, securing its resetting to the cen-
ter position.
This also has the effect of a reaction spring to give appropriate control feeling to the operator.

2-73
3) OPERATION
The operation of the pilot valve will be described on the basis of the hydraulic circuit diagram
shown below and the attached operation explanation drawing.
The diagram shown below is the typical application example of the pilot valve.

5 6

3
1
3
P T

2 4

2-70

1 Pilot valve 3 Main pump 5 Hydraulic motor

2 Brake pump 4 Main control valve 6 Hydraulic cylinder

2-74
(1) Case where handle is in neutral position

T
4-3

P
4-1

Port 1 Port 3

140WAL2RL06

The force of the spring (4-3) that determines the output pressure of the pilot valve is not applied
to the spool (4-1). Therefore, the spool is pushed up by the spring (5) to the position of port (1, 3)
in the operation explanation drawing. Then, since the output port is connected to tank port T only,
the output port pressure becomes equal to tank pressure.

2-75
(2) Case where handle is tilted

6-2

4-1

Port 1 Port 3

140WAL2RL07

When the push rod (6-2) is stroked, the spool (4-1) moves downwards.
Then port P is connected with port (1) and the oil supplied from the brake pump flows through
port (1) to generate the pressure.
When the pressure at port (1) increases to the value corresponding to the spring force set by tilt-
ing the handle, the hydraulic pressure force balances with the spring force. If the pressure at port
(1) increases higher than the set pressure, port P is disconnected from port (1) and port T is con-
nected with port (1). If it decreases lower than the set pressure, port P is connected with port (1)
and port T is disconnected from port 1.
In this manner the secondary pressure is kept at the constant value.
Besides, in some type, when the handle is tilted more than a certain angle, the upper end of the
spool contacts with the inside bottom of the push rod and the output pressure is left to be con-
nected with port P.

2-76
GROUP 6 ACCELERATOR PEDAL

1. STRUCTURE
The casing has the oil inlet port P (primary pressure), and the oil return port T (tank). In addition the
secondary pressure is taken out through port A.

25

42

T
P

17032RP01

Port Port name Port size

P Pilot oil inlet port
T T Pilot oil return port PF 1/4
A
A Pilot oil output port
P

Hydraulic circuit

17032RP01(2)

2-77
 GROUP 7 BRAKE DEVICE

■ BRAKE VALVE

1. STRUCTURE
The body has the oil inlet port P1, P2 (primary pressure), and the oil outlet port T1, T2 (tank). In
addition the secondary pressure is taken out through brake cylinder port BR1 (front axle) and BR2
(rear axle).

18
17-2
19
20
17
17-1
17-4
23
17-3
21
26 25
28 22
27 29
24
15
5 16
8 2
9 T1 30
31 BL1 29
32 P1 3
12 BR1
7 1
11 T2 BL2
13 14
P2 6
BR2
10
4
14W92BV01

1 Lower body 13 Spring guide 21 Lock pin 1

2 Upper body 14 Snap ring 22 Lock pin 2
3 Spool 15 DU bushing 23 Torsion spring 1
4 Plug 16 Pedal plate 24 Torsion spring 2
5 Holder 17 Pedal assy 25 Retainer ring
6 Lower spring 17-1 Pedal 26 E-ring
7 Upper spring 17-2 Lock plate 27 Hex bolt
8 Main spring 17-3 Hex bolt 28 Hex nut
9 Spring retainer 17-4 Plain washer 29 Socket head bolt
10 O-ring 18 Pedal cover 30 Spring washer
11 O-ring 19 Latch 31 Plate washer
12 Oil seal 20 Rubber cover 32 Retainer ring

Port Port name Port size

P1 Port
P2 Port
BL1
T1 BR1 Brake cylinder port
BR1
P1
BR2 Brake cylinder port
PF 3/8
BL1 Pluging
BL2 Pluging
BL2
T2 T1 Drain port
BR2 P2
14W72BV02
T2 Drain port

2-78
2. FUNCTION
1) PURPOSE
The purpose of the brake valve is to sensitively increase and decrease the braking pressure when
the brake pedal is actuated.
2) READY POSITION
When the braking system is ready for operation, its accumulator pressure acts directly on port P1/
P2 of the brake valve. A connection is established between ports BR1/BR2 and port T1/T2 so that
the wheel brakes ports BR1/BR2 are pressureless via the returns ports T1/T2.
3) PARTIAL BRAKING
When the brake valve is actuated, an amount of hydraulic pressure is output as a ratio of the foot
force applied.
The main spring (8) beneath pedal plate (16) is designed in such a way that the braking pressure
changes depending on the angle. In the lower braking pressure range, the machine can be
slowed sensitively.
When the braking process is commenced, the upper spool (3) is mechanically actuated via main
spring (8), and the lower spool (3) is actuated hydraulically by spool (3). As spools (3) move
downward, they will first close returns T1/T2 via the control edges, thus establishing a connection
between accumulator port P1/P2 and ports BR1/BR2 for the wheel brake cylinders. The foot force
applied now determines the output braking pressure. The control spools (3) are held in the control
position by the force applied (spring assembly) above the spools and the hydraulic pressure below
the spool (balance of forces).
After output of the braking pressure, spools (3) are in a partial braking position, causing ports P1/
P2 and T1/T2 to close and holding the pressure in ports BR1/BR2.
4) FULL BRAKING POSITION
When pedal (17-1) is fully actuated, an end position of the brakes is reached and a connection
established between accumulator ports P1/P2 and brake cylinder ports BR1/BR2. Returns T1/T2
are closed at this point.
When the braking process ended, a connection is once again established between brake cylinder
ports BR1/BR2 and return ports T1/T2, closing accumulator ports P1/P2.
The arrangement of spools in the valve ensures that even if one braking circuit fails the other
remains fully operational. This is achieved by means of the mechanical actuation of both spools
and requires slightly more pedal travel.
5) LIMITING THE BRAKING PRESSURE
Pedal restriction socket bolt (29) on pedal plate (16) below pedal assy (17) is used to limit the
braking pressure.
6) FAILURE OF A CIRCUIT
In the event of the lower circuit failing, the upper circuit will remain operational. Main spring (8) will
mechanically actuate spool (3). In the event of the upper circuit failing, the lower circuit will remain
operational since the lower spool (3) is mechanically actuated by main spring (8) and spool (3).

2-79
■ BRAKE SUPPLY VALVE

1. STRUCTURE
The brake supply valve consists of the following parts.

4
6
3

2 7

5 8 5 1 5

140WA2BSV01

Item Part name Size Qty Remark

1 Manifold block - 1 -
2 Logic valve - 1 K1 port
3 Unloading valve - 1 K2 port
4 Relief valve - 1 K3 port
5 Check valve - 3 K4, 5, 6 ports
6 Relief valve - 1 K7 port
7 Plug PF 1/8" 9 -
8 Plug PF 1/4" 1 PGP port

2-79-1
2. FUNCTION
1) ASSEMBLY
This brake supply valve has the following functions.
(1) Brake pump overload prevention function - energy saving function
(2) Safety device function of brake braking system
(3) Brake braking pressure supply function

2) FUNCTION FOR EACH VALVE

Symbol Valve name Description Remark

This valve is operated by remote control according to
K1 Logic valve
the set pressure value of the unloading valve (K2).

This valve switches the operation of the pump to a Set pressure

no-load state by bypassing the pressure and flow rate - Cut-in set value
K2 Unloading valve discharged from the pump to the tank when a load 112±5 kgf/cm2
occurs in the braking system. - Cut-out set value
142±5 kgf/cm2

This valve functions to maintain the pressure of the Set pressure

K3 Relief valve
flow flowing into the “S1” port at the set pressure. 8 l/min @ 32+2 kgf/cm2
This valve prevents reverse flow against the pressure
K4 Check valve and flow rate formed in the braking system of the
brake.
This valve prevents the loss of pressure and flow
accumulated in the accumulators installed in the ACC1
K5, K6 Check valve and ACC2 ports. In other words, it prevents the back
flow of pressure and flow accumulated in the
accumulator.
This valve functions as a safety device to prevent
Set pressure
K7 Relief valve breakage or damage to the system when overload or
30 l/min @ 173+2 kgf/cm2
abnormal pressure occurs within the brake system.

2-79-2
3) DETAIL FUNCTION AND USAGEE
(1) Brake pump overload prevention function - energy saving
① The pressure and flow discharged from the brake pump are supplied to the brake device through
the brake supply valve.
② When the engine rotation (rpm) of the machine increases, the rotation of the brake pump
increases, increasing the discharge pressure and flow rate.
③ This increased pressure and flow rate causes loss of pump power source and fluid energy.
This valve prevents energy loss by reducing power source and fluid energy loss.
④ When the braking system pressure of the brake exceeds the set pressure value of the unloading
valve (K2), the pilot spool of the unloading valve is activated and the flow formed in the drain line
of the logic valve (K1) is bypassed to the “T” line.
⑤ Therefore, when the flow rate of the drain line of the logic valve is bypassed, the spool of the
logic valve is pushed and the pressure and flow rate discharged from the brake pump are
bypassed to the tank, thereby converting the pump's operating state to a no-load state.
⑥ Also, when the brake system pressure falls below the set pressure value of the unloading valve,
the pilot spool of the unloading valve is closed.
⑦ As the pilot spool of the unloading valve closes, a flow rate is formed in the drain line of the logic
valve, and the spool of the logic valve also closes. When the spool of this logic valve is closed,
the pressure and flow discharged from the pump are supplied to the brake braking device.
⑧ The discharge pressure and flow rate of the pump are called cut-out when bypassed to the tank,
and cut-in when supplied to the brake device.
⑨ When this valve is shipped, the unloading valve setting value is as follows.
Unit : kgf/cm2
Reference value Set value
Flow rate
Cut-in Cut-off Cut-in Cut-off

30 l/min 112±5 142±5 112±5 142±5

2-79-3
(2) Safety device function of brake braking device
① If an overload occurs within the brake system due to an external force, an abnormal pressure
rise may occur, which may cause damage or breakage to various brake systems.
② To prevent such machine problems, a relief valve (K7) is installed.
③ If the system pressure within the brake system exceeds the set pressure value of the relief valve,
the relief valve operates to maintain the set pressure value of the relief valve.
④ In other words, the pressure above the set pressure value of the relief valve is returned to the
tank to relieve the abnormal rise in pressure caused by overload within the system, thereby
preventing damage and breakage of various devices within the system.
⑤ When this valve is shipped, the relief valve setting value is as follows.

Flow rate Reference value Set value Remark

30 l/min 173±2 kgf/cm2 173±2 kgf/cm2 -

(3) Brake braking pressure supply function

① When the brake pedal is pressed, the pressure accumulated in the accumulator falls below the
cut-in set pressure value of the unloading valve.
At this time, the pilot spool of the unloading valve is closed.
② As the pilot spool of the unloading valve closes, flow is formed in the drain line of the logic valve
and the spool of the logic valve also closes.
③ When the spool of this logic valve is closed, the pressure and flow discharged from the pump
are supplied to the accumulator and brake device.
④ Also, when the brake pressure is formed and exceeds the cut-out pressure value of the
unloading valve, the logic valve and unloading valve operate to bypass the pressure and flow
rate discharged from the pump to the tank, thereby maintaining the no-load start of the pump
and prevents rise the pressure within the brake system.
⑤ Check valves (K5, K6) separate each brake circuit (front, rear) so that they do not affect the
opposite brake and maintain each brake function.

2-79-4
3. ASSEMBLY DRAWING AND WORK TOOLS
See below for assembly, disassembly, and work tools for the brake supply valve.
※ The designated tools and tightening torque must be observed.

3
Disassembly Assembly
direction direction
2

7
4

4
6
140WA2BSV02

No. Part name Screw spec Torque (kg · cm) Assembly tool
1 Logic valve M20×1.5 480 Torque wrench/7/8" hex socket
2 Unloading valve M20×1.5 480 Torque wrench/7/8" hex socket
3 Relief valve M16×1.5 350 Torque wrench/3/4" hex socket
4 (3ea) Check valve UNF7/8-14" 400 Torque wrench/1" hex socket
5 Relief valve M16×1.5 350 Torque wrench/3/4" hex socket
6 (9ea) Plug PF 1/8 100 Torque wrench/4 mm wrench socket
7 Plug PF 1/4 300 Torque wrench/6 mm wrench socket

2-79-5
4. PRECAUTION WHEN DISASSEMBLING AND ASSEMBLING
1) Before assembling and disassembling, clean the surrounding area thoroughly to ensure there are
no contaminants.
2) When disassembling and assembling parts, be sure to use the assembly torque and tools
specified on the previous page.
3) Refer to the picture on the previous page for assembly and disassembly directions.
4) When reassembling after disassembly and inspection, be careful to prevent contaminants from
entering the valve.
5) When disassembling and assembling all parts, be sure to wash them and then reassemble them.

5. INSPECTION ITEMS AND DETAILS FOR EACH PART WHEN AN ERROR OCCURS
Problem Inspection item Inspection detail and method Repair
1. Check whether foreign 1. Disassemble the logic valve and check Removing foreign
substances and contaminants whether contaminants such as foreign matter substances,
have entered the logic valve. or sludge have entered between the spool cleaning, and
Brake pressure is not supplied

and body. assembling

2. Check whether foreign 2. Disassemble the relief valve and check Removing foreign
substances and contaminants whether contaminants such as foreign matter substances,
enter the relief valve. or sludge have entered between the poppet cleaning, and
and body. assembling
3. Check the discharge amount 3. Install a pressure gauge on the “PGP” port to Repair or
and discharge pressure of the check the pressure value discharged from replacement
brake pump the brake pump.
- Check at engine low speed
- Check with the unloading valve fully closed.
- Reference set value; 173±2 kgf/cm2
1. Check the unloading valve 1. Check the cut-in pressure value of the Readjust pressure
cut-in pressure value unloading valve (K2) value
- Install a pressure gauge on the “PGP” port to
measure the pressure value at cut-in.
Brake warning lamp comes ON

- Reference set value; 112±5 kgf/cm2

2. Check pressure switch 2. If the pressure measurement value in item 1 Repair or
operation above is normal but the brake warning lamp replacement
continues to come on, check the contact
status of the pressure switch.
3. Check the degree of 3. Check the element screen in the brake filter Cleaning or
contamination of the brake for contamination by foreign substances. replacement
filter element.
4. Check whether foreign 4. Refer to paragraphs 1 and 2 of “Brake Removing foreign
substances and contaminants pressure is not supplied” above. substances,
are entering the logic valve cleaning, and
and relief valve. assembling

2-79-6
Problem Inspection item Inspection detail and method Repair
The cycle of cut-in and cut-out is fast
1. Check whether the O-ring and 1. After disassembling each check valve (K4, Replace check
back-up ring installed on each K5, K6), check whether the O-ring and back- valve
check valve are damaged. up ring are damaged.
2. Check foot brake valve 2. Remove the hydraulic hose installed at the Replace foot
leakage outlet port (BR1, BR2) of the foot brake valve brake valve
and check the amount of oil leakage.
- Check without pressing the brake pedal-
Neutral state
- Reference set value; Refer to foot brake
valve leakage management standards

6. CHECK BRAKE PRESSURE IN CASE OF ABNORMALITY

1) INSTALLATION OF PRESSURE GAUAGE

Pressure gauge installation port Screw Remark

PGP PF1/4" O-ring boss -

2) CHECK PRESSURE VALUE DURING INSPECTION

Unloading valve operating status

Pressure value confirmation port
Cut-in Cut-off

PGP 112±5 kgf/cm2 142±5 kgf/cm2

2-79-7
 GROUP 8 TRANSMISSION

1. STRUCTURE

Lubrication pressure(S) Breather(EN) Emergency actuation

parking brake(PN)

Pressure relief
valve(UN)

Gauge port(Low speed, M)

Gauge port(High speed, J)

Oil drain hole Oil filler hole

Oil level check

Shift pressure port(Low speed, P2)

Shift pressure port(High speed, P1)
K B

High speed breather(EB, brake)

Low speed breather
(EK, clutch)

Speed transmitter(N)

VIEW X

VIEW Y
180W9A2TM01

2-80
2. TRANSMISSION DIAGRAM

P
Pressure valve
M
Gearshift valve

Shift modulation valve T

B K M2 M1

K B Rotary
Upper chassis/undercarriage

S
K B
M Gearshift piston

J Check valve
EB Change over
check valve
EK Nab
LB Leakage check
valve
Pressure limiting
valve

LK
Pump for lube oil &
control pressure shift interlock

= Pressure line transmission control

= Tank line transmission control
UN Output = Lubrication pressure
Output
= Suction line lube oil pump
PN = Transmission lubrication oil
S = Emergency actuation parking brake
EN
14W7A2TM02

Measuring points-Transmission/Shift interlock : Measuring points-Valve block :

J : High speed (brake) M : System pressure transmission control
M : Low speed (clutch)
S : Lubrication pressure Connections-Valve block :
P : System pressure transmission control
Connections-Transmission/Shift interlock : T : Tank
B : Brake B : Brake
K : Clutch K : Clutch
PN : Emergency actuation parking brake
Solenoid valves-valve block :
M1 : Solenoid valve (low speed)
M2 : Solenoid valve (high speed)

Port Name Size Port Name Size

P1 (B) Shift pressure, High speed M16×1.5 M Gauge port, Low speed M10×1.0
P2 (K) Shift pressure, Low speed M16×1.5 S Lubrication pressure port M10×1.0
J Gauge port, High speed M10×1.0 PN Parking brake lubricant Grease nipple

2-81
3. OPERATION OF TRANSMISSION
1) DESCRIPTION

1 2 3 4 5 6 11

INPUT

OUTPUT OUTPUT

10 9 8
14W7A2TM03

1 Cup spring 5 Planetary drive 9 Output flange-front axle

2 Input shaft 6 Lub oil pump 10 Travel motor attachment
3 Disk brake 7 Spur gear drive 11 Shift interlock
4 Disk clutch 8 Output flange-rear axle

Coaxially-mounted variable displacement travel motor (10) with specific displacement 107 cm3/rev.
The 2-speed powershift transmission comprises a planetary drive (5), a 2 shaft spur gear drive (7)
with output flanges to front and rear axle.
The powershift mechanism for the planet drive comprises a rotating multi-disk clutch (4) underneath
a multi-disk brake (3) rigidly connected to the housing. Both are closed by spring pressure (2) and
released hydraulically.
The shift interlock (11) prevents downshifts at high machine speeds and thus prevents over-rotation
of the travel motor. If the low speed gear is selected while the high speed gear is engaged and input
speed is above approx. 1000 rpm, the low speed gear shift is inhibited and only performed if input
speed is below this limit. With higher viscosity oil (cold starting), the downshift is performed at a
lower input speed. Upshifts are always possible.The speed-dependent interlock is effective in both
directions. It does not prevent the possibility of over-rotation when the machine is coasting. For this,
a drive brake valve should be fitted to the travel motor.

2-82
2) LOW SPEED (forward & reverse)

Ring gear Planetary carrier

Low speed
pilot pressure
applied

P1(B)
INPUT
P2(K)

Spur gear 1
Spring
Spur gear 2

Piston Clutch
Brake
OUTPUT OUTPUT

14W7A2TM04

In low speed operation, the internal gear of the planetary drive is backing upon the closed, case-
rigid brake. In this speed the piston chamber of the brake is unpressurized, so that the elastic force
and additionally the hydraulic pressure of the clutch piston is acting upon the disk pack.
At this time the clutch is open, i.e. the hydraulic released.

2-83
3) HIGH SPEED (forward & reverse)

Ring gear Planetary carrier

High speed pilot

pressure applied

P1(B)
INPUT
P2(K)

Spur gear 1
Spring
Spur gear 2

Piston Clutch
Brake
OUTPUT OUTPUT

14W7A2TM05

In high speed operation, the clutch is held closed under spring pressure and the brake is
hydraulically opened.
When a gear shift occurs-for example from high speed to low speed gear- the oil from the brake
piston space is fed back to the tank through a restrictor (change over check valve) due to the spring
pressure acting on the brake piston. At the same time the clutch is filled with oil and opened.
Required oil flow is necessary for the transmission control to ensure the clutch is open before the
brake begins to transmit torque.
A shift modulation valve is also integrated in the transmission. This modulates the pressure
sequence at the brake during a upshift in order to achieve good shift quality.
The gear shift equipment also has the function of a parking brake. When the brake is operated-for
example with high speed gear engaged-the clutch is closed and is statically loaded.

2-84
4) BRAKES

Travel high & low speed

pilot pressure not applied

P1(B)

P2(K)

OUTPUT OUTPUT

14W7A2TM06

When the travel high/low speed pilot pressure is not applied in the piston space, the piston
compress against the multi disk pack due to the spring force. Thus the parking brake is engaged.

2-85
4. TECHNICAL DATA
1) GENERAL DATA
(1) Max input power : 110 kW
(2) Max input torque : 78.5 kgf·m
(3) Max output speed : 3500 rpm
(4) Hydraulic motor : 140 cm3/rev
(5) Transmission ratio
Gear step : 4.06
·Low speed gear : 4.87
·High speed gear : 1.20
(6) Shift interlock
Downshift possible at operating temperature with input speed 1000 rpm (downshift point lower
when oil temperature cold).
(7) Disconnection device
For towing away machine auxiliary release device for parking brake.
(8) Brake
Parking brake. Necessary brake deceleration by controlled locking of planetary drive. Braking
torque depends on opening pressure set at brake valve (13 bar).
(9) Output flange
Bolts for propshaft connection : M10×1.0 (class 10.9)
(10) Transmission weight : 135 kg (300 lb)
2) TRANSMISSION CONTROL
Following data are valid for oil temperature 30˚C to 40˚C in hydraulic tank, measured at
connections at powershift transmission (see structure and diagram).
(1) Control pressure
① At connection P1 and P2 at Low/High engine speed : 33+2 kgf/cm2
② Definition of lubricants : API CF-4, SAE 10W-30
(2) Oil flow
① Min oil flow at 24+1 kgf/cm2 counter pressure (low engine speed) : 5.5ℓ/min
② Max oil flow : 25ℓ/min
(3) Residual pressure
① Max residual pressure in control line to tank connection P1 and P2 : 1.0 kgf/cm2
(4) Leakage oil transmission control
① Pressure in input housing connection (E) max : 1.0 kgf/cm2
② Max oil flow (low speed actuated) : 1ℓ/min

2-86
GROUP 9 TR
TRAVEL
AVEL CONTROL VALVE

1. STRUCTURE

CT2

CT1

T
TRAVEL
PILOT TP
AC1

M1 CT3

CH

M2

14W7A2TCV02

AC1 M2

Ø1.2 Port name Port size

M1 P, T, AC1 PF 1/2
CT3 TP PF 3/8
CT2
M1, M2, CH PF 1/4
P
TP
(TRAVEL
PILOT) T

CT1

CH (CHOCK)

Hydraulic circuit

2-87
2. COMPONENT

4 7

7
AC1

M1 6
CT3
T

1
1
CT
2
CT

7 7

2, 5

14W7A2TCV01

1 Body 5 Coil
2 Solenoid valve 6 Orifice
3 POD valve 7 Plug
4 Check valve

2-88
GROUP 10 STEERING VALVE

1. STRUCTURE
1) TYPE 1 (without joystick)

L R

T AP A

LS

SECTION A-A

L R

Port Port name Port size

L Left port
R Right port
3/4-16UNF
T Tank port
P Pump port
LS Load sensing port 7/16-20UNF

P T LS
Hydraulic circuit 31U6-30020-E

2-89
2) TYPE 2 (joystick steering)

L R
T

LS

L R

Port Port name Port size

L Left port M18x1.5
R Right port M18x1.5
T Tank port M22x1.5
R
P Pump port M22x1.5
Electronics
L
LS Load sensing port M12x1.5

LS

P LS T
Hydraulic circuit 81K5-00030-E

2-90
2. COMPONENTS
1) TYPE 1 (without joystick)

31U6-30020-P

1 Dust seal 13 Shaft 31 Relief valve assy

2 Housing, spool, sleeve 16 Distributor plate 32 Shock valve
3 Ball 17 Gear wheel set 33 Ball
4 Ball 18 O-ring 34 Bushing
5 O-ring 19 End cover 50 Mounting pin
7 Bearing assy 20 Washer 51 Cardan shaft
10 Ring 23 Screw 54 Valve and housing
11 Cross pin 24 name plate
12 Spring set 30 Relief valve assy

2-90-1
2) TYPE 2 (joystick steering, 1/2)
93
300
301
302

95
7
14
18 303
304
16 305

12
1
205
310

209 202
311
13

40 A
64
62
61
63
41
3
B
224
253
81 225

6
C
330 87
331 86
332
85 D
80
246
247

313 213 249

312 214 248
207 215
314
216
81K5-00030-P1

1 Spool/sleeve set 81 Ball 247 Coil

3 Housing 85 Screw 248 Nut
6 O-ring 86 Spring 249 O-ring
7 Shaft seal 87 Valve cone 253 Plug
9 Dust seal ring 93 Plug 300 Lock ring
12 Cross pin 95 Port relief valve cartridge 301 O-ring
13 Shaft 202 Spool 302 O-ring
14 Spring set 205 Plug 303 Backup ring
16 Ring 207 Plug 305 Filter
18 Bearing 209 Plug 310 O-ring
40 O-ring 213 Spring 311 O-ring
41 O-ring 214 Cone pilot supply 312 O-ring
61 Ball 215 Spool pilot supply 313 O-ring
62 Spring 216 Plug 314 O-ring
63 Valve seat 224 Spool 330 O-ring
64 Adjust screw 225 Plug 331 O-ring
80 Pin 246 Spool 332 O-ring

2-90-2
TYPE 2 (joystick steering, 2/2)

34
A
30

B
120
116

122 39
C
242
D
117
5
4
115
241
321
312
322
243 323

320
39
E
E
36

35
31 204
27

233

81K5-00030-P2

4 Screw 39 O-ring 241 Spring

5 Ball 115 Gear set 242 Spool
27 Short screw 116 Valve plate 243 Plug
30 Gear set 117 Valve plate 320 O-ring
31 Screw 120 Shaft 321 O-ring
34 Valve plate 122 Valve housing 322 O-ring
35 Washer 204 PVE 323 O-ring
36 End cover 233 Plug

2-90-3
 GROUP 11 FRONT AXLE AND REAR AXLE

1. OPERATION
· The power from the engine passes through main pump, travel motor and transmission and drive
shafts, and is then sent to the front and rear axles.
Inside the axles, the power passes from the bevel pinion to the bevel gear and is sent at right angles.
· At the same time, the speed is reduced and passes through the both differentials to the axle shafts.
The power of the axle shafts is further reduced by planetary-gear-type final drives and is sent to the
wheels.
1) FRONT AXLE
Oil filler/level check/ Brake line port
drain port (M14x1.5)

Planetary gear Differential gear

A Oil filler & level check port
Grease nipple

Outer steering angle 27 10'

Inner steering angle 35

Brake breather Oil drain port VIEW A

140WA2AX01

2) REAR AXLE
Oil filler/level check/
drain port B

Planetary gear Differential gear

Oil filler & level check port

Brake breather

Brake line port Oil drain port

(M14x1.5) VIEW B
140WF2AX01A

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2. DIFFERENTIAL

Rear axle
Differential

Front axle

140WF2AX03

The differential is installed on the front and rear axle to transfer the driving torque from the axle to
the wheels. The differential transfers half of the output torque of the transmission via the universal
drive shaft to the planetary gear of the wheel hubs and transfers the rpm and torque from the gear
via the pinion and the ring.
In addition, the differential also servers as an equalizer when going around curves. If the
mechanical connection from the transmission to the universal drive shaft, differential, shaft, and
planetary gears to the wheels would be rigid, every steering movement would strain the axle
construction and would result in increased tire wear.
The equalizing function comes from the special construction of the differential. The power input
from the input flange to the pinion shaft, ring and differential housing to the equalizing axle in the
differential housing meshes the four equalizing tapered gears with the axle gears, which are
located in the equalizing axles. This changes the relative direction of rotation between the shafts
meshed with the side gears. This means that one shaft turns clockwise and the other
counterclockwise, and one shaft turns faster than the other.
This balancing movement has the disadvantage that when traveling off road, traction is reduced on
uneven ground, on loose ground or on snow or ice only wheel per axle is engaged. This
disadvantage can be corrected in part by installing a self locking differential.

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3. TIRE AND WHEEL

17032TI01

1 Wheel rim 3 Flap 5 Stone resister ring

2 Tire 4 Tube 6 Valve assembly

1) The tire acts to absorb the shock from the ground surface to the machine, and at the same time
they must rotate in contact with the ground to gain the power which drives the machine.
2) Various types of tires are available to suit the purpose. Therefore it is very important to select the
correct tires for the type of work and bucket capacity.

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