UENR3883
November 2012
Hydraulic System
Printed in U.S.A.© 2012 Caterpillar, All Rights Reserved
950H, 962H, and IT62H Wheel Loader
950H:
N1A4397-UP
JAD410-UP
M1G2111-UP
K5K2761-UP
962H:
N4A2116-UP
M3G679-UP
K6K517-UP
MAL123-UP
IT62H:
M5G468-UP
ONE POSITION TWO POSITION THREE POSITION
VENTED
PRESSURIZED
RETURN ABOVE FLUID LEVEL RETURN BELOW FLUID LEVEL
LINES CROSSING LINES JOINING
TWO - WAY THREE - WAY FOUR - WAY
SPRING CONTROL VALVES RESTRICTION LINE RESTRICTION
(FIXED)
PUMP
(2 - SECTION)
SPRING
(ADJUSTABLE)
VARIABILITY LINE RESTRICTION
(VARIABLE)
PRESSURE
COMPENSATION
PUMP
(VARIABLE & PRESSURE
COMPENSATED)
MEASUREMENT
PRESSURE TEMPERATURE FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVE ENVELOPES VALVE PORTS
FLUID CONDITIONERPUMP OR MOTOR
FLUID POWER SYMBOLS
UNIDIRECTIONAL
BIDIRECTIONAL
RELEASED PRESSURE
EXTERNAL RETURN INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
HYDRAULIC PUMPS
ACCUMULATORS
SPRING LOADED GAS CHARGED
SOLENOID
OR MANUAL
SOLENOID
& PILOT
SOLENOID &
PILOT OR MANUAL
SOLENOID SERVO THERMAL DETENT
HYDRAULIC & PNEUMATIC CYLINDERS
DOUBLE ACTINGSINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
2 POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW IN
EITHER
DIRECTION
3 POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
AB
PT
AB
PT
SHIFTED POSITION INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
MAIN AUX
LINE RESTRICTION
(VARIABLE & PRESSURE
COMPENSATED)
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FLUID STORAGE RESERVOIRS
CROSSING & JOINING LINES
VALVES
PILOT CONTROL SYMBOLS
COMBINATION CONTROLS
BASIC COMPONENT SYMBOLS
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
INTERNAL
SUPPLY PRESSURE
COMPLETE
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
HYDRAULIC SYMBOLS (ELECTRICAL)
ELECTRICAL SYMBOLS TABLE
325-AG135 PK-14
HARNESS IDENTIFICATION CODE THIS EXAMPLE
INDICATES WIRE 135 IN HARNESS “AG”
325-PK-14
WIRE GAUGE
WIRE COLOR
CIRCUIT NUMBER
IDENTIFICATION
WIRE NUMBER IDENTIFICATION CODES
CURRENT STANDARD
PREVIOUS STANDARD
ELECTRICAL SCHEMATIC EXAMPLE HYDRAULIC SCHEMATIC EXAMPLE
325-PK
WIRE COLOR
CIRCUIT NUMBER
IDENTIFICATION
B
WIRE
WIRE
(EXAMPLE VALVE)
CURRENT STANDARD
TRANSDUCER
(FLUID)
M
ELECTRIC MOTORTRANSDUCER
(GAS / AIR)
G
GENERATOR
PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH
(ADJUSTABLE)
TEMPERATURE
SWITCH
PRESSURE
SWITCH
TEMPERATURE
SWITCH
LEVEL
SWITCH
FLOW
SWITCH
ELECTRICAL SYMBOLS (ELECTRICAL)
A
CIRCUIT NUMBER
IDENTIFICATION
WIRE
COLOR
WIRE GAUGE
T
UENR3883
30 Page, (Dimensions: 39 inches x 28 inches)
FRONT OF FRAME
HAND METERING UNIT
COMMAND CONTROL STEERING
FAN AND BRAKE SYSTEM
AXLE OIL COOLING
14
11
10
12
3
2
35
G2
61 24255720
13 4655
54
G5G4
45
27
43
51
34
60
37
G5
G8G11
G9
G10
19
8221823
40 4
29
5
17
1
39
49
26
28
NOT SHOWN
INSIDE (29)TANK GP - HYDRAULIC
B
C
SOS
G6
G12
G7
G1
G3
7
41
44
9
1521
55
38
50
42
6
Tap
Number
Description
Schematic
Location
G1 Brake Accumulator Pressure C-8, E-2
G2 Implement Pump Discharge Pressure E-7
G3 Implement Pump Load Sense Pressure B-7
G4
G5
Steering Pump Discharge Pressure B-6
G6
Steering Pump Load Sense Pressure A-3, D-1
G7
Fan Pump Discharge Pressure B-7
G8
Fan Pump Load Sense Pressure B-8
G9
CCS Steering Neutral Pilot Pressure C-3
G
10
CCS Steering Left Pilot Pressure D-2
G11
CCS Steering Right Pilot Pressure D-2
G12
CCS Steering Resolved Pilot Pressure C-3
Case Drain Air Bleed A-8
B Front Brake Pressure F-2
C Rear Brake Pressure F-2
SOS Scheduled Oil Sampling B-8
Tap Location
Pressure and Sampling
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator - Brake 213-8773 1 F-2
Accumulator - Pilot 355-9981 2 F-4
Accumulator - Ride Control 325
-7159 3 F-5
Actuator GP - Parking Brake 129-8090 4 F-1
Breather 258-2829 5 A-7
Connector - Orifice 122-2340 6 A-3
Control GP - Foot Brake 271-0263 7 E-6
Cooler - Hyd Oil
Standard
Attachment
244-5427
250-8327
8
B-8
Core AS - Axle Oil Cooler 313-7721 9 C-7
Cylinder GP - Lift (Left) 242-4272 10 F-6
Cylinder GP - Lift (Right) 242-4271 11 F-2
Cylinder GP - Quick Coupler 311-1463 12 D-6
Cylinder GP - Steering 314-9338
13 B-1, D-2
Cylinder GP -Tilt
950 Standard
962 Standard
High Lift
Logger
242-4270
247-0497
245-7491
245-7487
14
F-7
Filter - Axle Oil Cooler 251-6351 15 C-6, F-8
Filter GP - Oil 337-4102 16 A-7
Filter GP - Oil 330-9358 17 B-8
Manifold -Fan Drive and Brake Charge
242-1307
352-1587
18
E-2
C-8
Motor GP - Fan 246-6152 19 B-8
Pump and Motor GP - Secondary Steering 275-8544 20 A-7
Pump GP - Axle Oil Cooler 215-3013 21 C-6
Pump GP - Fan and Hyd Brake 254-5146 22 B-8
Pump GP - Implement 292-8767 23 B-7
Pump GP - Metering (HMU) 349-6093 24 A-3
Pump GP - Steering 241-9299 25 B-6
Pump GP - Transmission 241-8692 26 B-7
Screen AS - Command Control Steering 154-2883 27 D-2
Screen AS - Implement/Steering Return 9T-9227 28 B-8
Tank GP - Hydraulic 340-5659 29 A-7
Valve - Anti-drift Solenoid 328-4314 30 F-5, F-6, F-7
Valve - Load Sense
Relief 346-0475 31 A-6, E-7
Valve - Margin Relief 328-0730 32 E-4
Valve - Pressure Reducing Pilot Supply 335-1074 33 E-4
Valve - Pressure Reducing Pilot Supply 114-1267 34 C-2
Valve - Quick Coupler 180-8585 35 D-7
Valve - Ride Control Relief 4T-7581 36 E-5
Valve - Shuttle CCS Pilot 8J-6875 37 C-3
Valve GP - Check Backpressure 353-7179 38 C-5
Valve GP - Brake Control (Parking) 106-1774 39 F-1
Valve GP - Foot Bra
ke 215-3687 40 F-2
Valve GP - Check Anti-Drainback 307-5393 41 B-8
Valve GP - Check Axle Oil-Cooler 130-5202 42 C-6
Valve GP - Check Command Control Steering 111-7775 43 D-3
Valve GP - Check Cooler Bypass 244-1426 44 B-8
Valve GP - Command Control Steering 124-8635 45 D-1
Valve GP - HMU Steering 142-4000 46 B-2
Valve GP - Make-up Lift 234-4869 47 F-6
Valve GP - Main Control
Two Function without Ride Control
Two Fu
nction with Ride Control
Three Function without Ride Control
Three Function with Ride Control
With Ride Control (Logger)
261-4171
261-3682
261-4172
261-3683
256-3643
48
F-4
Valve GP - Manual Lowering 112-1817 49 B-7, D-6, F-7
Valve GP - Manual 8T-6907 50 A-7
Valve GP - Pilot Command Control Steering 147-1790 51 D-3
Valve GP - Relief (Auxiliary) 272-2334 52 F-5
Valve GP - Relief (Tilt) 332-1987 53 F-6
Valve GP - R
elief Pump Backup 132-5258 54 B-5
Valve GP - Relief Steering Cylinder Crossover 129-8222 55 B-5
Valve GP - Relief Tilt (Logger) 332-1985 56 F-2
Valve GP - Secondary Steering 141-2597 57 B-7
Valve GP - Shuttle 235-6157 58 E-5
Valve GP - Solenoid 313-7668 59 E-5, E-6, F-5, F-6
Valve GP - Steering Neutralizer (CCS) 321-5283 60 C-2, D-2
Valve GP - Steering Neutralizer (HMU) 296-5662 61 B-6
Component Location
16
36
53
56
52
47
59
32
30
31
33
48
58
MAIN CONTROL VALVE
Solenoid
Valve
Solenoid Location Solenoid Name
Schematic
Location
E1 Fan / Brake Valve Demand Speed Fan Solenoid
C-8
E2 Implement Valve - Lift Lower Solenoid E-6
E3 Implement Valve - Lift Raise Solenoid
F-6
E4 Implement Valve - Ride Control Ride Control Balance Solenoid
E-5
E5 Implement Valve - Ride Control Ride Control Head End Check Solenoid F-5
E6 Implement Valve - Ride Control Ride Control Rod End Check Solenoid F-5
E7 Implement Valve - Tilt Dump Solenoid E-6
E8 Implement Valve - Tilt Rack Back Solenoid
F-6
E9 Implement Valve Implement Pilot Support Solenoid F-4
E10 Implement Valve - 3rd Function 3rd Function Port A Solenoid F-5
E11 Implement Valve - 3rd Function 3rd Function Port B Solenoid E-5
E12 Implement Valve - Lift Lower Anti-drift Solenoid F-6
E13 Implement Valve - Tilt Dump Anti-drift Solenoid
F-7
E14 Quick Coupler Valve Enable Solenoid D-7
SOLENOID VALVE REFERENCE
UENR3883
30 Page, (Dimensions: 39 inches x 28 inches)
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.
SCHEMATIC PART NUMBER: 241-0475, CHANGE: 11, VERSION: -
BRAKE SYSTEM PART NUMBER: 244-1398, CHANGE: 01, VERSION: -
MEDIA NUMBER: UENR3883
THIS SCHEMATIC IS FOR THE 950H, 962H AND IT62H WHEEL LOADER HYDRAULIC SYSTEM
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
IMPLEMENT PUMP OUTPUT
PRIMARY STEERING PUMP CIRCUIT
STEERING CIRCUIT
IMPLEMENT PILOT SUPPLY OIL
AUXILIARY CIRCUIT
IMPLEMENT PUMP LOAD SENSING CIRCUIT
SUPPLY LINE
TILT CYLINDER CIRCUIT
LIFT CYLINDER CIRCUIT
SECONDARY STEERING CIRCUIT
BRAKE CHARGE VALVE AND FAN CONTROL CIRCUIT
MAIN RELIEF VALVE LOAD SENSING CIRCUIT
BRAKE CONTROL CIRCUIT
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
YY
C
A
B
A
B
C
HMU STEER AND 3PC IMPLEMENT
BRAKE SYSTEM
COMMAND CONTROL STEERING ATTACHMENT
G12
SOS
G7
G6
G1
G3
G4
G1
B
C
G5
G10
G9
G11
G8
G5
TO SERVICE
BRAKE VALVE
UPPER PORT
(REAR AXLE)
TO SERVICE
BRAKE VALVE
LOWER PORT
(FRONT AXLE)
JACKET
WATER
(COOLANT)
REAR AXLE
A1
A2
PS
E1
F
LS
P
T
PB
B
A
PA
P
HMU
T
X
B
L
S
M
L
R
LS
T
P
IMPLEMENT RETURN
AXLE OIL COOLER SUPPLY
AXLE OIL COOLER RETURN
QUICK COUPLER SUPPLY
IMPLEMENT LOAD SENSE RELIEF/PILOT RETURN
IMPLEMENT LOAD SENSE SIGNAL
IMPLEMENT PUMP DISCHARGE
A
LS
P
G
T
LS
S
L
S
B
A
LS
PA
PB
T
P
P
T
TRANSMISSION
CONTROL
A1
A2
PS
F
LS
P
T
TO FAN MOTOR
TO CASE DRAIN
MANIFOLD
TO BRAKE
LIGHTS
TO TRANSMISSION CONTROL
NO
NC
C
C
RELEASE
APPLY
FRONT AXLE
REAR AXLE
NC
C
HYDRAULIC
TANK
NC
NO
C
PORT A LEVER FORWARD,
LEFT HAND LINE ON BOOM
(WHEN VIEWED FROM CAB)
PORT B LEVER REARWARD,
RIGHT HAND LINE ON BOOM
(WHEN VIEWED FROM CAB)
FRONT AXLE
A1
B1
A2
B2
A3
B3
B4
A4
E13
E12
E9
E5
E6
E8 E3 E10
RACK
RAISE
PORT
BACK
A
RACK
RAISE
PORT
BACK
A
HOLD
HOLD
E4
HOLD
PORT
DUMP
LOWER
B
FLOAT
LOWER/
DUMP
FLOAT
PORT
B
E7 E2 E11
IMPLEMENT RETURN
AXLE OIL COOLER SUPPLY FLOW
AXLE OIL COOLER RETURN FLOW
QUICK COUPLER SUPPLY
IMPLEMENT LOAD SENSE RELIEF/PILOT RETURN
IMPLEMENT LOAD SENSE SIGNAL
IMPLEMENT PUMP DISCHARGE
PRIMARY PILOT SUPPLY - CCS STEERING ATTACHMENT
E14
IMPLEMENT LOAD SENSE RELIEF/PILOT RETURN
PRIMARY PILOT SUPPLY - CCS STEERING ATTACHMENT
FILTER-MAGNETIC
(AXLE OIL COOLER)
251-6351
VALVE GP
MANUAL
LOWERING
112-1817
CYLINDER-TILT
242-4270 (950 STANDARD)
247-0497(962 STANDARD)
245-7491(HIGH LIFT)
245-7487 (LOGGER)
CYLINDER GP- LIFT (LH)
242-4272
CYLINDER GP
LIFT (RH)
242-4271
ACCUMULATOR-RIDE CONTROL
325-7159
VALVE GP
TILT
332-1987
VALVE GP
332-1987 (TILT)
332-1985 (TILT-LOGGER)
VALVE GP
SOLENOID (ANTI-DRIFT)
328-4314
VALVE GP
SOLENOID (RACK BACK)
313-7668
VALVE GP
MAKE-UP (LIFT)
234-4869
VALVE
LOAD SENSE RELIEF
346-0475
VALVE GP
SOLENOID (DUMP)
313-7668
VALVE GP
SOLENOID
(LOWER)
313-7668
VALVE GP
SOLENOID
313-7668
VALVE GP
SOLENOID
(ANTI-DRIFT)
328-4314
VALVE GP
SOLENOID
(ANTI-DRIFT)
328-4314
VALVE GP
RELIEF
RIDE
CONTROL
4T-7581
VALVE GP
SOLENOID
313-7668
VALVE GP
SHUTTLE
235-6157
VALVE GP-RELIEF
( AUXILIARY)
272-2334
ACCUMULATOR GP
PILOT OIL
355-9981
VALVE
MARGIN RELIEF
328-0730
VALVE
PRESSURE REDUCING
335-1074
VALVE GP - MAIN CONTROL
TWO FUNCTION WITHOUT RIDE CONTROL: 261-4171
TWO FUNCTION WITH RIDE CONTROL: 261-3682
THREE FUNCTION WITHOUT RIDE CONTROL: 261-4172
THREE FUNCTION WITH RIDE CONTROL: 261-3683
THREE FUNCTION WITH RIDE CONTROL (LOGGER): 256-3643
CYLINDER GP
QUICK COUPLER
311-1463
CYLINDER GP
QUICK COUPLER
311-1463
ACCUMULATOR
BRAKE
213-8773
ACCUMULATOR
BRAKE
213-8773
MANIFOLD GP-CONTROL
(FAN DRIVE AND BRAKE CHARGE)
352-1587
MOTOR GP-FAN
246-6152
FILTER GP-OIL
330-9358
VALVE GP
CHECK
ANTI-DRAINBACK
307-5393
VALVE GP
CHECK
COOLER
BYPASS
244-1426
COOLER - HYD OIL
STANDARD: 244-5427
ATTACHMENT: 250-8327
PUMP GP
FAN AND HYD BRAKE
254-5146
CORE AS
AXLE OIL COOLER
313-7721
VALVE GP-CHECK
(AXLE OIL COOLER BYPASS)
130-5202
VALVE GP-CHECK
(AXLE OIL COOLER BYPASS)
130-5202
PUMP GP - AXLE OIL COOLER
215-3013
FILTER-MAGNETIC
(AXLE OIL COOLER)
251-6351
VALVE GP-CHECK
BACKPRESSURE
353-7179
FILTER GP-OIL
337-4102
TANK GP - HYDRAULIC
340-5659
BREATHER
258-2829
PUMP GP - TRANSMISSION
241-8692
PUMP GP - IMPLEMENT
292-8767
PUMP GP - STEERING
241-9299
PUMP AND MOTOR GP
SECONDARY STEERING
275-8544
VALVE GP
SECONDARY STEERING
141-2597
SCREEN AS
STEERING RETURN
9T-9227
VALVE GP - HMU STEERING
142-4000
VALVE GP
STEERING
NEUTRALIZER
(HMU)
VALVE GP
STEERING
NEUTRALIZER
(HMU)
CONNECTOR
ORIFICE
122-2340
CONNECTOR
ORIFICE
122-2340
PUMP GP
METERING (HMU)
349-6093
VALVE GP-RELIEF
STEERING CYLINDER
CROSSOVER
129-8222
VALVE GP - RELIEF
PUMP BACKUP
132-5258
CYLINDER GP
STEERING
314-9338
CYLINDER GP
STEERING
314-9338
VALVE GP - RELIEF
PUMP BACKUP
132-5258
CYLINDER GP
STEERING
314-9338
CYLINDER GP
STEERING
314-9338
VALVE GP-RELIEF
STEERING CYLINDER
CROSSOVER
129-8222
VALVE GP
COMMAND CONTROL STEERING
124-8635
VALVE
PRESSURE REDUCING
PILOT SUPPLY
114-1267
VALVE GP
STEERING
NEUTRALIZER (CCS)
321-5283
SCREEN AS
COMMAND
CONTROL STEERING
154-2883
COMMAND CONTROL STEERING
111-7775
VALVE GP - CHECK
VALVE GP - PILOT
COMMAND CONTROL STEERING
147-1790
VALVE - SHUTTLE
CCS PILOT
8J-6875
PUMP GP - FAN
254-5146
SWITCH AS
PARKING BRAKE PRESSURE
174-4312
ACTUATOR AS
PARKING BRAKE
129-8090
VALVE GP - PARKING BRAKE
106-1774
ACCUMULATOR - SERVICE BRAKE:
213-8773
VALVE GP
FOOT BRAKE
215-3687
CONTROL GP
FOOT BRAKE
271-0263
SWITCH AS
BRAKE PRESSURE
175-3244
MANIFOLD GP
FAN AND
BRAKE CHARGE
242-1307
VALVE
BREAKER
RELIEF
220-0814
VALVE-QUICK COUPLER
180-8585
VALVE GP-MANUAL LOWERING
112-1817
VALVE GP
MANUAL LOWERING
112-1817
VALVE GP
MANUAL
8T-6907
G2
G9
