INTERACTIVE SCHEMATIC

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 UENR6347-03
April 2016

926M, 930M and 938M Wheel Loader

Hydraulic System
926M: 930M: 938M:
LTE1-1899 KTG1-1599 J3R1-1699

Volume 1 of 2: Drive Circuits

Volume 2 of 2: Implement Circuits

© 2016 Caterpillar, All Rights Reserved Printed in U.S.A.

COMPONENT LOCATION
Volume 1 of 2 - DRIVE CIRCUITS
Part Schematic Machine
Description
Number Location Location
Accumulator Gp - Brake 360-9207 1 E-7
Accumulator Gp - Charge 373-6953 2 E-6
Cooler Gp - Hydraulic Oil (926M, 930M) 352-0357 3 C-4
Cooler Gp - Hydraulic Oil (938M) 354-8742 3 C-4
Cooler Gp - Transmission Oil (938M) 383-7596 4 D-3
Filter Gp - Gearbox 349-3667 5 E-3
Filter Gp - Hydraulic Oil 421-5475 6 F-6
Manifold Gp - Brake Accumulator 349-9089 7 E-7
Manifold Gp - Hystat Interlock Valve 347-0785 8 E-5
Manifold Gp - Hystat Loop 345-1707 9 D-3, B-2
Motor Gp - Hystat (115cc) 307-3077 10 C-3
Motor Gp - Hystat (152cc) (926M, 930M) 307-3082 11 C-1
Motor Gp - Hystat (170cc) (938M) 341-7648 11 C-1
Motor Gp - Radiator/Hydraulic Fan 398-7462 12 A-8
Motor Gp - Radiator/Hydraulic Fan (Reversing) 398-7465 13 B-8
Orifice Gp - Motor Flushing Connector 9X-2614 14 D-2
Pedal Gp - Brake 423-7159 15 E-8
eCharge/LubPump Gp 398-7459 16 D-4
Pump Gp - Fan/Brake (W/Brake Charging Valve) 423-0094 17 D-7
Pump Gp - Hystat (926M) 341-7638 18 D-6
Pump Gp - Hystat (930M, 938M) 307-3065 18 D-6
Sensor Gp - Pressure (Brake Charge) 344-7391 19 D-8
Sensor Gp - Pressure (Hystat Loop FWD) 349-1178 20 E-6
Sensor Gp - Pressure (Hystat Loop REV) 349-1178 21 C-5
Sensor Gp - Pressure (Park Brake) 344-7391 22 E-7
Transmission Ar - Gearbox (926M, (930M) 451-2453 23 E-2
Transmission Ar - Gearbox (938M) 439-4201 23 E-2
Valve Gp - Check (Hyd Oil Cooler Bypass) 348-2078 24 C-6
Valve Gp - Check (Hystat Flushing) 370-2280 25 D-1
Valve Gp - Check (Pilot Supply) 123-4750 26 E-5
Valve Gp - Check (Xmsn Oil Cooler Bypass) 385-9391 27 D-3
Valve Gp - Park Brake (938M) 357-0377 28 E-7
Valve Gp - Solenoid (Hystat Interlock) 456-1772 29 E-5
Valve Gp - High Altitude / Cold Start Not Shown 388-9447 30 F-6
COMPONENT LOCATION
Volume 2 of 2 - IMPLEMENT CIRCUITS
Machine Schematic
Description Part Number
Location Location
Accumulator Gp - Pilot 226-0420 31 E-8
Accumulator Gp - Ride Control (926M) 373-7017
32 F-3
Accumulator Gp - Ride Control (930M, 938M) 373-6960
Accumulator Gp - Ride Control (926M) 373-7016
33 F-3
Accumulator Gp - Ride Control (930M, 938M) 373-6962
Breather - Hydraulic Tank 258-2829 34 A-2
Cylinder Gp - Fusion Coupler 375-0724 35 D-7
Cylinder Gp - Wide Coupler 353-9375 36 D-5
Cylinder Gp - High Lift Tilt (926M, 930M) 351-8514
37 F-4
Cylinder Gp - High Lift Tilt (938M) 351-8515
Cylinder Gp - Lift (926M) 339-5590
Cylinder Gp - Lift (930M) 339-5593 38 F-4
Cylinder Gp - Lift (938M0 347-3853
Cylinder Gp - Steering (926M, 930M) 339-5595
39 D-1
Cylinder Gp - Steering (938M) 347-3852
Cylinder Gp - Tilt (926M) 339-5592
Cylinder Gp - Tilt (930M) 339-5594 40 F-4
Cylinder Gp - Tilt (938M) 347-3854
Manifold Gp - Rear Frame Return 347-8096 41 D-8
Manifold Gp - Steering 346-5095 42 D-2
Orifice Gp - Ride Control PC 366-8973 43 E-3
Pump Gp - Hand Metering (926M, 930M) 307-3053
44 E-2
Pump Gp - Hand Metering (938M) 341-7623
Pump Gp - Hand Metering (W/Dual Mode Steering - 926M, 930M) 307-3081
45 C-2
Pump Gp - Hand Metering (W/Dual Mode Steering - 938M) 341-7639
Pump Gp - Implement Pump (926M) 378-2837
Pump Gp - Implement Pump (930M) 307-3044 46 C-5
Pump Gp - Implement Pump (938M) 341-7662
Pump Gp - Secondary Steering (W/Integrated Relief) 307-3051 47 D-1
Sensor Gp - Pressure (Implement Pump Discharge) 344-7391 48 E-8
Sensor Gp - Pressure (Primary Steering) 344-7391 49 D-3
Tank Gp - Hydraulic 349-8199 50 A-3
Tube As - Front Frame Return 433-1417 51 D-5
Valve Gp - Bank 2 (Implement) (926M) 421-5435
Valve Gp - Bank 2 (Implement) (930M) 421-5438 52 F-8
Valve Gp - Bank 2 (Implement) (938M) 421-5441
Valve Gp - Bank 3 (Implement) (926M) 421-5436
Valve Gp - Bank 3 (Implement) (930M) 421-5439 53 F-8
Valve Gp - Bank 3 (Implement) (938M) 421-5442
Valve Gp - Bank 4 (Implement) (926M) 421-5437
Valve Gp - Bank 4 (Implement) (930M) 421-5440 54 F-8
Valve Gp - Bank 4 (Implement) (938M) 421-5443
Valve Gp - Ball (Dead Engine Lower) 112-1817 55 F-5
Valve Gp - Check (Implement Backpressure) 352-1045 56 E-8
Valve Gp - Check (Ride Control Supply) 201-7657 57 F-3
Valve Gp - Check (Secondary Steering) 9T-1013 58 D-2, E-1
Valve Gp - Check (Steering Backpressure) 192-2684 59 D-7
Valve Gp - Check (Steering Inlet) 175-0447 60 D-3
Valve Gp - Differential Lock (926M, (930M) 233-7133
61 F-8, C-8
Valve Gp - Differential Lock (938M) 365-6860
Valve Gp - Dual Mode 247-4503 62 C-2
Valve Gp - Quick Coupler 352-1108 63 D-6
Valve Gp - Ride Control 280-9978 64 F-3
Valve Gp - Shutoff (Petcock) 6V-7238 65 D-7
Additional
Motor Gp - Electric (Secondary Steering) 117-3915 66 C-1
TAP LOCATION
Volume 1 of 2 - DRIVE CIRCUITS

Tap Schematic
Description
Number Location
P7 Charge Pressure F-6
P8 Charge Fill F -6
P9 Gearbox SOS Gauge E-3
P10 Hystat Forward Drive Pressure D-3
P11 Hystat Reverse Drive Pressure C-2
P12 Hydraulic SOS Gauge F-6
P13 Gearbox Pressure E- 3
P 14 Lube Pressure E-3
P15 Clutch Pressure E- 2
P16 Front Service Brake Pressure E-8
P17 Rear Service Brake Pressure E-8
TAP LOCATION
Volume 2 of 2 - IMPLEMENT CIRCUITS

Tap Schematic
Description
Number Location
P1 Steering Discharge Pressure C-2, E-1
P2 Steering Loadsense Pressure D-3
P3 Implement Discharge Pressure E-6
P4 Implement Loadsense Pressure D-4
P5 Implement Pilot Pressure E-6
P6 Quick Coupler Pressure D-6
P18 Differential Lock Pressure C-8
FLUID POWER SYMBOLS
BASIC COMPONENT SYMBOLS

MAIN AUX.
PUMP: VARIABLE and
PUMP or MOTOR FLUID CONDITIONER SPRING CONTROL VALVES RESTRICTION LINE RESTRICTION 2-SECTION PUMP PRESSURE COMPENSATED
(FIXED)

VARIABILITY SPRING LINE RESTRICTION PRESSURE HYDRAULIC PNEUMATIC LINE RESTRICTION ATTACHMENT
(ADJUSTABLE) (VARIABLE) COMPENSATION ENERGY TRIANGLES VARIABLE and PRESSURE
COMPENSATED

VALVE ENVELOPES
VALVES
VALVE PORTS

ONE POSITION TWO POSITION THREE POSITION TWO-WAY THREE-WAY FOUR-WAY

CONTROL VALVES CHECK VALVES

AB AB

P T P T
BASIC SPRING SHUTTLE PILOT
NORMAL POSITION SHIFTED POSITION INFINITE POSITION
SYMBOL LOADED CONTROLLED

FLUID STORAGE RESERVOIRS

VENTED PRESSURIZED RETURN ABOVE FLUID LEVEL RETURN BELOW FLUID LEVEL

MEASUREMENT ROTATING SHAFTS

PRESSURE TEMPERATURE FLOW UNIDIRECTIONAL BIDIRECTIONAL

COMBINATION CONTROLS

SOLENOID SOLENOID SOLENOID SOLENOID and SERVO THERMAL DETENT

or MANUAL and PILOT PILOT or MANUAL

MANUAL CONTROL SYMBOLS

PUSH-PULL LEVER MANUAL SHUTOFF GENERAL MANUAL PUSH BUTTON PEDAL SPRING

RELEASED PRESSURE PILOT CONTROL SYMBOLS

REMOTE SUPPLY PRESSURE

EXTERNAL RETURN INTERNAL RETURN SIMPLIFIED COMPLETE INTERNAL

SUPPLY PRESSURE

ACCUMULATORS CROSSING AND JOINING LINES HYDRAULIC AND PNEUMATIC CYLINDERS

SPRING LOADED GAS CHARGED LINES CROSSING LINES JOINING SINGLE ACTING DOUBLE ACTING

HYDRAULIC PUMPS HYDRAULIC MOTORS INTERNAL PASSAGEWAYS

FIXED VARIABLE DISPLACEMENT FIXED VARIABLE DISPLACEMENT INFINITE THREE TWO

DISPLACEMENT NON-COMPENSATED DISPLACEMENT NON-COMPENSATED POSITIONING POSITION POSITION

UNIDIRECTIONAL UNIDIRECTIONAL

FLOW IN ONE PARALLEL CROSS FLOW ALLOWED IN

BIDIRECTIONAL BIDIRECTIONAL DIRECTION FLOW FLOW EITHER DIRECTION
ELECTRICAL SYMBOLS
Hydraulic Symbols (Electrical)

G M
Transducer Transducer Generator Electric Motor
(Fluid) (Gas / Air)

Pressure Switch Pressure Switch Temperature Switch Electrical Wire

(Adjustable)

Electrical Symbols (Electrical)

Pressure Temperature Level Flow

Symbol Symbol Symbol Symbol

Wire Number Identification Codes

Electrical Schematic Example Hydraulic Schematic Example

Current Standard Current Standard

Harness identification code
This example indicates
wire 135 in harness "AG". Wire
Circuit Number Wire Color
Identification

325-AG135 PK-14
325-PK
Circuit Identification Wire Color Wire Gauge
Number

Previous Standard
Wire Color
Wire

325-PK-14
B A
Circuit Number Wire Gauge
Identification (EXAMPLE VALVE)
 8 7 6 5 4 3 2 1
(6) FILTER GP-OIL
HYD OIL
421-5475

P8

P12 P7
G
F F

(30) VALVE GP
HIGH ALTITUDE / COLD START
456-1772

(8) MANIFOLD GP
HYSTAT INTERLOCK
347-0785
(15) PEDAL GP-BRAKE (1) ACCUMULATOR GP
423-7159 BRAKE ACCUMULATOR
360-9207
To
P13 P14 Front P15
(28) VALVE GP Axle (23) TRANSMISSION AR - GEARBOX

Dual Mode
Steering
P17 PARK BRAKE
(22) SENSOR GP-PRESS 439-4201 :(938M)

Manifold
Steering
357-0377
PARK BRAKE 451-2453 :(926M, 930M)

Front
Sec.
344-7391
T1 (5) FILTER GP-O (BSC)
GEARBOX
E 349-3667 E
To Brakes

E
P16
G

Pilot Drain
T U
(2) ACCUMULATOR GP Z
P C CHARGE ACCUMULATOR
373-6953 Y

(7) MANIFOLD GP
BRAKE ACCUMULATOR
(19) SENSOR GP - PRESSURE E T
349-9089
(BRAKE CHARGE)
344-7391 HMU
(20) SENSOR GP-PRESS
P9
A1 A2 HYSTAT LOOP(FORWARD)
349-1178 Rear Drain (27) VALVE GP - CHECK
(29) VALVE GP-SOLENOID
Ms S F HYSTAT INTERLOCK
Manifold (COOLER BYPASS)
385-9391 (4) COOLER GP
(17) PUMP GP - FAN/BRAKE 366-8955
(W/ BRAKE CHARGING VALVE) XMSN OIL
423-0094 938M: 383-7596 To
(18) PUMP GP
HYSTAT PUMP Rear
(930M, 938M): 307-3065 P10 Axle
(926M) 341-7638
SW (9) MANIFOLD GP

Implement
HYSTAT LOOP

Steering
345-1707
D B1 B2 D

Lube

M
Pump (14) ORIFICE GP
MOTOR FLUSHING
9X-2614 (25) VALVE GP-CHECK
S2 (11) MOTOR GP
HYSTAT FLUSHING
HYSTAT (170cc)
370-2280
Hystat Charge (938M): 341-7648
Fan Brake S1 Pump (16) PUMP GP
(10) MOTOR GP
(926M, 930M): 307-3082
1:1 Drive Ratio Pump HYSTAT (115cc)
Valve CHARGE & LUBE
398-7459 307-3077
M1 B B M1 SA

P U U

U L Mp P

(24) VALVE GP -
HYD OIL COOLER BYPASS T2 T1
C 348-2078 C

(21) SENSOR GP - PRESSURE A A

HYSTAT LOOP (REVERSE)
349-1178

G T1
A T2 G

P11
Hydraulic
B Tank (9) MANIFOLD GP
HYSTAT LOOP
345-1707 :(926M, 930M)
C (3) COOLER GP - HYDRAULIC OIL
926M 930M: 352-0357
(13) MOTOR GP - RADIATOR/HYDRAULIC FAN (REVERSING) 938M: 354-8742
398-7465

B B

Secondary
LINE PATTERNS
Steer
Pressure Line
(12) MOTOR GP - RADIATOR/HYDRAULIC FAN Pilot / Load Sensing Pressure HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
398-7462 MAIN PUMP OUTPUT
Drain / Return Lines LUBE PUMP CIRCUIT
STEERING CIRCUIT
Component Group FAN/BRAKE CHARGE PUMP
LUBE PUMP SUPPLY CIRCUIT
Attachment BRAKE CIRCUIT
A DRAIN / RETURN LINE
Air Line HYSTAT CIRCUIT

CALLOUTS
A A
YY Taps (Pressure, Sampling, Sensor - by letter)

B THIS SCHEMATIC IS FOR THE 926M, 930M, AND 938M WHEEL LOADER HYDRAULIC SYSTEM
C VOLUME 1 of 2: DRIVE CIRCUITS
MEDIA NUMBER: UENR6347-03
SCHEMATIC PART NUMBER: 443-6472, CHANGE: 00, VERSION: -
Fan Motor (Standard) Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
in neutral and with parking brake set.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
Refer to the Parts Manual using a specific serial number prefix in SIS before ordering parts from this schematic.

8 7 6 5 4 3 2 1
 8 7 6 5 4 3 2 1
(52) VALVE GP - BANK 2 (IMPLEMENT)
(926M): 421-5435 Ride Control
(930M): 421-5438
(938M): 421-5441
(53) VALVE GP - BANK 3 (IMPLEMENT) (55) VALVE GP - BALL (39) CYLINDER GP
(926M): 421-5436 DEAD ENGINE LOWER STEERING
(930M): 421-5439 112-1817 347-3852
(938M): 421-5442 (37) CYL GP - HIGH LIFT TILT
(926M, 930M): 351-8514 P
(54) VALVE GP - BANK 4 (IMPLEMENT)
(926M): 421-5437 (938M): 351-8515
(32) ACCUMULATOR GP - RIDE CONTROL
(930M): 421-5440 (40) CYL GP - TILT
(938M): 421-5443 (926M): 373-7017
(926M): 339-5592
F (930M): 339-5594 R (930M, 938M): 373-6960 F
(938M): 347-3854
Tilt Cylinder
(61) VALVE GP
DIFFERENTIAL LOCK H
(926M, 930M): 233-7133
(33) ACCUMULATOR GP - RIDE CONTROL
Aux Aux (926M): 373-7016
Tilt Lift (930M, 938M): 373-6962
T 1 2
T To A B A B A B A B
(38) CYL GP - LIFT
P P5 T S
P C (926M): 339-5590 (64) VALVE GP LP RP
PPG
Lx
(930M): 339-5593 Lift RIDE CONTROL
(938M): 347-3853
Cylinders (57) VALVE GP - CHECK 280-9978
RIDE CONTROL SUPPLY
201-7657
Ls

(43) ORIFICE GP
RIDE CONTROL PC
366-8973
DL

TP LS PP
(31) ACCUMULATOR GP ACC RCS
PILOT (58) VALVE GP - CHECK
226-0420 (44) PUMP GP - HAND METERING UNIT SECONDARY
E P (926M, 930M): 307-3053 STEERING E
(938M): 341-7623 9T-1013
(56) VALVE GP - CHECK
IMPLEMENT T
BACK PRESSURE P3 P1
352-1045 CS PG

(48) SENSOR GP - PRESSURE

IMPLEMENT PUMP
DISCHARGE
344-7391

(39) CYLINDER GP - STEERING

(51) TUBE AS (926M, 930M): 339-5595
FRONT FRAME (938M): 347-3852
LS C2
RETURN MANIFOLD
E T 433-1417

(41) MANIFOLD GP (65) VALVE-SHUTOFF

REAR FRAME RETURN PETCOCK VALVE
347-8096 6V-7238
C1
GP
P6 (36) CYLINDER GP
P WIDE COUPLER
D 353-9375 D
(59) VALVE-CHECK R (63) VALVE GP C1 C2
Park Brake STEERING
(35) CYL GP
QUICK COUPLER
BACKPRESSURE 352-1108
Valve FUSION
192-2684
COUPLER
(60) VALVE AS - CHECK
375-0724
STEERING INLET
175-0447 (58) VALVE GP - CHECK
SECONDARY
STEERING
LP RP
9T-1013
(47) PUMP GP
SECONDARY STEERING
(42) MANIFOLD GP (W/ INTEGRATED RELIEF)
(61) VALVE GP
P4 P2 (49) SENSOR GP - PRESS
STEERING D 307-3051
DIFFERENTIAL LOCK PRIMARY STEERING
346-5095
(926M, 930M): 233-7133 344-7391
(938M): 365-6860
P1
X1 X2

T
T P18
B S
C1 C2
P
P DL
(62) VALVE GP
DUAL MODE

M
STEERING
247-4503
T P
C C
TP LS PP
(66) MOTOR GP
(46) PUMP GP - IMPLEMENT ELECTRIC
(926M): 378-2837
(SECONDARY STEERING)
(930M): 307-3044
B1 B2 117-3915
(938M): 341-7662

(45) PUMP GP - HAND METERING UNIT

To To (W/DUAL MODE STEERING)
(926M, 930M): 307-3081
Charge Gear (938M): 341-7639
Circuit Box
Hystat
Pump B1 B2

Lube

M
Pump

Implement Pump Steering Pump Charge From Gear Box

1:1 Drive Ratio Pump S2

B B
L2 L4 L3

S1 L1 S2

LINE PATTERNS
Pressure Line HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
PILOT PUMP OUTPUT
Pilot / Load Sensing Pressure MAIN PUMP OUTPUT
LUBE PUMP CIRCUIT
Drain / Return Lines AUXILIARY 1 CURCUIT
LOAD SENSE CIRCUIT
(34) BREATHER Component Group STEERING CIRCUIT
HYDRAULIC TANK
FAN/BRAKE CHARGE PUMP
258-2829 Attachment SUPPLY LINE
QUICK COUPLER CIRCUIT
Air Line DIFFERENTIAL LOCK CIRCUIT
AUXILIARY 2 CURCUIT
CALLOUTS DRAIN / RETURN LINE

A Fan Motor TILT CYLINDER CIRCUIT

A
Return YY Taps (Pressure, Sampling, Sensor - by letter) LIFT CYLINDER CIRCUIT
LUBE PUMP SUPPLY CIRCUIT
Fan Motor
Case Drain
(50) TANK GP
HYDRAULIC TANK THIS SCHEMATIC IS FOR THE 926M, 930M, AND 938M WHEEL LOADER HYDRAULIC SYSTEM
349-8199
VOLUME 2 of 2: IMPLEMENT CIRCUITS
MEDIA NUMBER: UENR6347-03
SCHEMATIC PART NUMBER: 443-6472, CHANGE: 00, VERSION: -
Brake Pedal Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
Fan/Brake Cooler Cooler in neutral and with parking brake set.
Valve Suction Bypass Return Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
Refer to the Parts Manual using a specific serial number prefix in SIS before ordering parts from this schematic.

8 7 6 5 4 3 2 1
LEFT SIDE VIEW
VIEW ALL CALLOUTS
25 P13 P14 P15 P8 P7 29 8

15 P17 P16

27 5 P9 23 6 13 12 P12
REAR VIEW
VIEW ALL CALLOUTS

3
RIGHT SIDE VIEW

19 24 18 21 VIEW ALL CALLOUTS

16

P11

10
17

P10

7 20 22 28 11 14
RIGHT SIDE VIEW
VIEW ALL CALLOUTS

2 1
FRONT CYLINDERS
VIEW ALL CALLOUTS

37 40

38 35
FRONTAL VIEW

IMPLEMENT VALVE

36
IMPLEMENT VALVE
VIEW ALL CALLOUTS

48

56 P5

P3
31

52 53 54
RIGHT SIDE VIEW
VIEW ALL CALLOUTS
65 41 59 P2 P6 44 45

34

63
50
55

32

33
P4

51
34
57

64

39 61

P18

43
STEERING MANIFOLD DETAIL
VIEW ALL CALLOUTS

42

P1

58

60

P4

49
STEERING PUMP DETAIL
VIEW ALL CALLOUTS

62

66 47