Posted on by

CAT 966H and 972H Wheel Loader Hydraulic System

INTERACTIVE SCHEMATIC
The Bookmarks panel will allow you to
quickly navigate to points of interest.
Click on any text that is BLUE and underlined.
These are hyperlinks that can be used to navi-
gate the schematic and machine views.
When only one callout is showing on a machine view this
button will make all of the callouts visible. This button is
located in the top right corner of every machine view page.
VIEW ALL CALLOUTS
Cover Page
Information
Schematic
Machine Views
Component Table
Tap Table
Fluid Power Symbols
Electrical Symbols
Front Frame
Rear Frame
Tap Views
Features
Options
Bookmarks
X
EC-C3
EC-C2
E-C60
EC-C1
E-C61
To set your screen resolution do the following:
RIGHT CLICK on the DESKTOP.
Select PROPERTIES.
CLICK the SETTINGS TAB.
MOVE THE SLIDER under SCREEN RESOLUTION
until it shows 1024 X 768.
CLICK OK to apply the resolution.
This document is best viewed at a
screen resolution of 1024 X 768.
FUNCTION
Zoom In
HOTKEYS (Keyboard Shortcuts)
Zoom Out
Fit to Page
Hand Tool
“CTRL” / “+”
KEYS
“CTRL” / “-”
“CTRL” / “0” (zero)
“SPACEBAR” (hold down)
Find
“CTRL” / “F”
RENR8828-04
January 2012
966H and 972H Wheel Loader
Hydraulic System
966H:
A6D1-UP
RYF1-UP
A6G1-UP
A6J1-UP
TAL1-UP
972H:
GTA1-UP
LCC1-UP
A7D1-UP
A7G1-UP
A7J1-UP
Printed in U.S.A.© 2012 Caterpillar, All Rights Reserved
COMPONENT TABLE
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator Gp - Pilot 355-9981 1 E-1
Accumulator. Gp - Ride Control 325-7131 2 F-2
Cylinder Gp - Lift 242-4274
242-4275
(LH)
(RH)
3
F-2
Cylinder Gp - Tilt
Lift
Tilt
Cylinder Gp - Tilt - 966 Logger (Atch)
(966 Standard)
(972 Standard)
Cylinder Gp - Tilt - (966 High Lift - Atch)
Tilt - (972 High Lift - Atch)
356-2220
356-2219
358-5190
358-5189
4
F-3
Filter Gp - Pump Case Drain 337-4102
5
F-3
F-3
6
7
Pump Gp - Implement 292-8768
8
C-8
9
Breather 258-2829 C-7
10
11
D-7
Screens - Return 9T-9227 C-7,8
12
13
Tank Gp - Hydraulic Oil 340-5659
15
C-7
Valve Gp - Backpressure 353-7179
14
E-7
Valve Gp - Relief (Auxiliary Function) 272-2334 E-1
16
Valve Gp - Relief (Make-Up - Lift) 234-4869 E-3
17
Valve Gp - Relief (Margin) 328-0730 E-1
18
Valve Gp - Relief (Ride Control) 4T-7581 E-2
F-1
Valve Gp - 2 Function w/o Ride Control
3 Function w/ Ride Control (Atch)
3 Function w/o Ride Control (Atch)
261-3945
2 Function w/ Ride Control (Atch) 261-2337
261-3972
261-2338
3 Function w/ Ride Control (Logger Atch) 256-3644
Valve Gp - Shuttle 235-6157 E-2
21
Valve Gp - Solenoid (Anti-Drift) 328-4314
26
27
E-3
Valve Gp - Solenoid (Pressure Reducing) 335-1074
28
E-1
Valve Gp - Solenoid (Pressure Reducing) 313-7668 E-1
Valve Gp - Dead Engine Lower 112-1817
22
E-7
Cylinder Gp - Steering (CCS Atch) 314-9336
23
B-5
Cylinder Gp - Steering HMU 314-9336 C-1
Neutralizer - HMU 296-5662 C-3
Neutralizer - (CCS Atch) 321-5283 A,B-6
Orifice 108-2144 B-3
Pump Gp - Steering 241-9157
141-2597
154-2883
24
D-6
Pump Gp - Secondary Steering Pump/Motor (Atch) 275-8544
25
C-7
Pump Gp - HMU Metering 349-6093 B-3
Valve Gp - Check (CCS Atch) 111-7775 B-6
C-7
B-5
A-6
Screen - (Atch)
Valve Gp - Check
29
Valve Gp - Pressure Reducing (Atch)
Valve Gp - Pilot (CCS Atch)
114-1267
164-4116
30
A-5
Valve Gp - Shuttle (Atch) 8J-6875
31
Valve - Manual Pump Case Fill 8T-6907 C-7,8
A-6
Valve Gp - Steering: Backup Relief 132-5258
32
C-2
Valve Gp - Steering (CCS Atch) 133-1728 B-5
Cooler - Hydraulic Oil 244-4498
33
D-8
Actuator - Parking Brake 154-8042 F-6
Filter Gp - Kidney Loop 330-9358
34
D-8
35
Motor Gp - Fan 161-8919
36
D-8
Motor Gp - Fan (Atch) 334-6234 D-8
Pump Gp - Fan 254-5147
37
D-8
Valve Gp - Charge (Fan Drive and Brake) 352-1587
38
E-8
Valve Gp - Check (Filter Anti-Drainback) 307-5393
39
D-8
Valve Gp - Cooler Bypass Check 244-1426
40
D-8
Valve Gp - Park Brake 106-1774
41
F-6
Valve Gp - Foot Brake 210-5587 F-7
42
43
44
45
46
47
Valve Gp - Diverter (Atch) 237-8180
48
C-8
Cylinder Gp - Quick Coupler (Atch) 311-1463
49
Valve Gp - Steering: Cross-Over Relief 129-8222 C-1
F-5
65
Valve Gp - Quick Coupler (Atch) 180-8585
50
E-5
51
Valve Gp - Sampling Port 8C-3451 D-8
Accumulator - Brake 198-9841 E-7,852
53
Breaker - Vaccum 220-0814 C-7
54
Component Locations
Quick Coupler (Attachment)
Axle Cooler System
Implement System
Steering System
Fan / Brake System
356-2220
Valve Gp - Relief (Load Sense) 346-0474 E-3
19
Valve Gp - Relief (Tilt) 332-1985 F-3
20
Valve Gp - Relief (Tilt - Logger Atch) 332-1986 F-3
55
56
57
58
59
60
61
Pump Gp - Transmission 241-8686 D-7
Miscellaneous
62
63
64
67
68
66
Valve Gp - Steering: HMU 142-3996 C-2
69
SAMPLING PORT LOCATION TABLE
Tap
Number
Description
Schematic
Location
8-FerusserP ekarB tnorF B
8-BerusserP ekarB raeRC
6-FerusserP ekarB kraP D
8-EBrake Accumulator Pressure 1G
4-EImplement Pump Discharge Pressure 2G
G3 D-7
G4 D-7Steering Pump Discharge Pressure
3-BSteering Pump Load Sense Pressure 5G
7-DFan Pump Discharge Pressure6G
8-DFan Pump Load Sense Pressure 7G
G8 A-7
G9 B-5
Tap Location
Pressure and Sampling
Implement Pump Load Sense Pressure
CCS Steering Neutral Pilot Pressure
CCS Steering Left Pilot Pressure
CCS Steering Right Pilot Pressure 1-EG10
6-A
Case Drain Air Bleed
G11
G12 D-8
8-DtroP gnilpmaS diulFSOS
CCS Steering Resolved Pilot Pressure
FLUID POWER SYMBOLS
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)
2-SECTION PUMP
MAIN
AUX.
SPRING
(ADJUSTABLE)
VARIABILITY
LINE RESTRICTION
(VARIABLE)
LINE RESTRICTION
VARIABLE and PRESSURE
COMPENSATED
PRESSURE
COMPENSATION
PUMP: VARIABLE and
PRESSURE COMPENSATED
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
MEASUREMENT
PRESSURE
TEMPERATURE
FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH-PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
HYDRAULIC PUMPS
FLUID STORAGE RESERVOIRS
CROSSING AND JOINING LINES
VALVE ENVELOPES
VALVE PORTS
BASIC COMPONENT SYMBOLS
FLUID CONDITIONER
PUMP or MOTOR
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVES
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
EXTERNAL RETURN
INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
COMPLETE
INTERNAL
SUPPLY PRESSURE
ACCUMULATORS
SPRING LOADED GAS CHARGED
SOLENOID
or MANUAL
SOLENOID
and PILOT
SOLENOID and
PILOT or MANUAL
COMBINATION CONTROLS
SOLENOID
SERVO
THERMAL
DETENT
HYDRAULIC AND PNEUMATIC CYLINDERS
DOUBLE ACTINGSINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
TWO
POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW ALLOWED IN
EITHER DIRECTION
THREE
POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
A B
P T
A B
P T
SHIFTED POSITION
INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
ELECTRICAL SYMBOLS
Hydraulic Symbols (Electrical)
325-AG135 PK-14
Circuit Identification
Number
Wire Color
Wire Gauge
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
A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical Wire
Pressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
T
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: 242-0337, CHANGE: 10, VERSION: -
MEDIA NUMBER: RENR8828-04
THIS SCHEMATIC IS FOR THE 966H AND 972H WHEEL LOADER HYDRAULIC SYSTEM
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
IMPLEMENT PILOT SUPPLY OIL
BRAKE COOLING CIRCUIT
IMPLEMENT PUMP OUTPUT
TRANSMISSION PUMP
PRIMARY STEERING PUMP CIRCUIT
IMPLEMENT PUMP LOAD SENSE CIRCUIT
STEERING CIRCUIT
FAN PUMP CIRCUIT
SUPPLY LINE
QUICK COUPLER CIRCUIT
BRAKE CONTROL CIRCUIT
AUXILIARY CIRCUIT
MAIN RELIEF VALVE LOAD SENSING CIRCUIT
DRAIN / RETURN LINE
TILT CYLINDER CIRCUIT
LIFT CYLINDER CIRCUIT
SECONDARY STEERING CIRCUIT
ELECTRICAL CIRCUITS
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
CALLOUTS
Taps (Pressure, Sampling, Sensor - by letter)
YY
(52) VALVE GP - CONTROL
138-1234
Callout Number
(Machine Location from
Component LocationsTable)
Component
Name
Part Number
HMU
PA
PB
T
B
A
P
L
R
P
T
LS
LS
P
T
PS
A1
A2
E1
F
IMPLEMENT PUMP DISCHARGE
IMPLEMENT LOAD SENSE SIGNAL
IMPLEMENT LOAD SENSE RELIEF/PILOT RETURN
QUICK COUPLER SUPPLY
IMPLEMENT RETURN
AXLE OIL COOLER RETURN
AXLE OIL COOLER SUPPLY
B
S
L
X
M
LS
REAR AXLE
P
T
T
P
LS
PA
PB
B
A
PORT A LEVER REARWARD,
LEFT HAND LINE ON BOOM
(WHEN VIEWED FROM CAB)
PORT B LEVER FORWARD,
RIGHT HAND LINE ON BOOM
(WHEN VIEWED FROM CAB)
RACK
BACK
DUMP
HOLD
DUMP
RAISE
LOWER/
FLOAT
RAISE
HOLD
LOWER
FLOAT
HOLD
PORT
A
PORT
B
PORT
A
PORT
B
E5
E6
E4
RACK
BACK
E2
E3
E7
E8
E9
E10
E11
E12
E13
B1
A1
A2
B2
A3
B3
A4
B4
PRIMARY PILOT SUPPLY - CCS STEERING ATTACHMENT
FRONT AXLE
E14
T
P
P
LS
LS
P
T
T
NC
NO
C
C
TO TRANSMISSION
CONTROL
TO BRAKE
LIGHTS
APPLY
RELEASE
AXLE
RESERVIOR
RESERVIOR
AXLE
TRANSMISSION
CONTROL
C
NO
NC
LS
COMMAND CONTROL STEERING (ATTACHMENT)
HMU STEERING (STANDARD CONFIGURATION)
(63) VALVE GP
OUTPUT
PRESSURE
210-5587
(64) VALVE GP
PARK BRAKE
106-1774
(53) ACTUATOR AS
PARK BRAKE
154-8042
(67) CYLINDER GP
QUICK COUPLER
311-1463
(68) VALVE GP
QUICK COUPLER
180-8585
(21) VALVE GP
MANUAL LOWER
112-1817
TILT CYLINDER
(6) 966 STANDARD 356-2219
(7) 972 STANDARD 356-2220
(8) 966 HIGH LIFT 358-5189
(9) 972 HIGH LIFT 358-5190
(10) 966 LOGGER 356-2220
(4) CYLINDER GP
LIFT - (LH)
242-4274
(5) CYLINDER GP
LIFT - (RH)
242-4275
(2) ACCUMULATOR
RIDE CONTROL
325-7131
(1) ACCUMULATOR
PILOT
355-9981
(23) VALVE GP
LOAD SENSE
RELIEF
346-0474
(32) VALVE GP
PRESSURE
REDUCING
313-7668
(32) VALVE GP
PRESSURE
REDUCING
313-7668
(32) VALVE GP
PRESSURE
REDUCING
313-7668
(25) VALVE GP
MARGIN
RELIEF
328-0730
(35) CYLINDER GP
STEERING
314-9336
(50) VALVE GP
STEERING
CROSSOVER RELIEF
129-8222
(48) VALVE GP
STEERING
BACKUP RELIEF
132-5258
(51) VALVE GP
STEERING (HMU)
142-3996
(11) FILTER GP
CASE DRAIN
337-4102
(3) BREATHER
258-2829
(14) TANK GP
HYDRAULIC
340-5959
(54) BREAKER
VACUUM
220-0814
(33) VALVE - MANUAL
PUMP CASE FILL
8T-6907
(13) SCREEN - RETURN
9T-9227
(66) VALVE GP
DIVERTER
237-8180
(56) FILTER GP
KIDNEY LOOP
330-9358
(61) VALVE GP
CHECK (FILTER
ANTIDRAINBACK)
307-5393
(55) COOLER
HYDRAULIC OIL
244-4498
(59) PUMP GP
FAN
254-5147
(62) VALVE GP
CHECK
(COOLER
BYPASS)
244-1426
(65) VALVE GP
SAMPLING PORT
8C-3451
(57) 161-8919
(58) 334-6234 (ATCH)
MOTOR GP - FAN
(60) VALVE GP
CHARGE (FAN
DRIVE AND
BRAKE)
352-1587
(52) ACCUMULATOR
BRAKE
198-9841
(21) VALVE GP - LOWER
(DEAD ENGINE)
112-1817
(20) VALVE GP
BACKPRESSURE
353-7179
(12) VALVE GP
IMPLEMENT
292-8768
(69) PUMP GP
TARNSMISSION
241-8686
(41) PUMP GP
STEERING
241-9157
(43) VALVE GP
CHECK
141-2597
(40) PUMP GP
SECONDARY
STEERING (ATCH)
275-8544
(47) VALVE GP
SHUTTLE (ATCH)
8J-6875
(45) VALVE GP
PILOT (CSS ATCH)
164-4116
(44) VALVE GP
CHECK
(CSS ATCH)
111-7775
(37) NEUTRALIZER
CCS (ATCH)
321-5283
(42) SCREEN (ATCH)
154-2883
(50) VALVE GP - STEERING
CROSSOVER RELIEF
111-7775
(46) VALVE GP - PRESSURE
REDUCING (ATCH)
114-1267
(48) VALVE GP - RELIEF
STEERING BACKUP
132-5258
(49) VALVE GP - STEERING
(CCS ATCH)
133-1728
(34) CYLINDER GP
STEERING
314-9336
(39) PUMP GP
HMU METERING
349-6093
(38) ORIFICE
108-2144
(36) NEUTRALIZER
HMU
296-5662
(22) VALVE GP - RELIEF
(AUX FUNCTION)
272-2334
IMPLEMENT VALVE GP
(15) 2 FUNCTION W/O RIDE CONTROL 261-3945
(16) 2 FUNCTION W/ RIDE CONTROL (ATCH) 261-2337
(17) 3 FUNCTION W/O RIDE CONTROL (ATCH) 261-3972
(18) 3 FUNCTION W/ RIDE CONTROL (ATCH) 261-3338
(19) 3 FUNCTION W/ RIDE CONTROL (LOGGER ATCH) 256-3644
(31) VALVE GP
PRESSURE
REDUCING
335-1074
(32) VALVE GP
SOLENOID
(PRESSURE
REDUCING)
313-7668
(32) VALVE GP
SOLENOID
(PRESSURE
REDUCING)
313-7668
(32) VALVE GP
SOLENOID
(PRESSURE
REDUCING)
313-7668
(26) VALVE GP - RELIEF
(RIDE CONTROL)
4T-7581
(29) VALVE GP - SHUTTLE
235-6157
(30) VALVE GP
SOLENOID
(ANTI-DRIFT)
328-4314
(30) VALVE GP
SOLENOID
(ANTI-DRIFT)
328-4314
(30) VALVE GP
SOLENOID
(ANTI-DRIFT)
328-4314
(27) VALVE GP
RELIEF (TILT)
332-1985
(28) VALVE GP
RELIEF
(LOGGER ATCH)
332-1985
(24) VALVE GP
RELIEF
(MAKE UP LIFT)
234-4869
G12
SOS
G7
G6
G3
G4
G2
G10
G5
G5
G1
G8
G11
G9
G10
SOLENOID VALVE REFERENCE
SOLENOID LOCATION SOLENOID NAME
E1 FAN / BRAKE VALVE DEMAND SPEED FAN SOLENOID
E2 IMPLEMENT VALVE - LIFT LOWER SOLENOID
E3 IMPLEMENT VALVE - LIFT RAISE SOLENOID
E4 IMPLEMENT VALVE - RIDE CONTROL RIDE CONTROL BALANCE SOLENOID
E5 IMPLEMENT VALVE - RIDE CONTROL RIDE CONTROL HEAD END CHECK SOLENOID
E6 IMPLEMENT VALVE - RIDE CONTROL RIDE CONTROL ROD END CHECK SOLENOID
E7 IMPLEMENT VALVE - TILT DUMP SOLENOID
E8 IMPLEMENT VALVE - TILT RACK BACK SOLENOID
E9 IMPLEMENT VALVE IMPLEMENT PILOT SUPPORT SOLENOID
E10 IMPLEMENT VALVE - 3RD FUNCTION 3RD FUNCTION PORT A SOLENOID
E11 IMPLEMENT VALVE - 3RD FUNCTION 3RD FUNCTION PORT B SOLENOID
E12 IMPLEMENT VALVE - LIFT LOWER ANTI-DRIFT SOLENOID
E13 IMPLEMENT VALVE - TILT DUMP ANTI-DRIFT SOLENOID
E14 QUICK COUPLER VALVE ENABLE SOLENOID
D
B
C

Leave a Reply

Your email address will not be published. Required fields are marked *