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CAT 966K and 972K Wheel Loader Hydraulic System

INTERACTIVE SCHEMATIC
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Cover Page
Information
Schematic
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Component Table
Tap Table
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Electrical Symbols
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Rear Frame
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X
EC-C3
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E-C61
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Hydraulic System
966K and 972K Wheel loader
PBG1-UP
PEM1-UP
TFS1-UP
Z4W1-UP
©
2012 Caterpillar, All Rights Reserved
Printed in U.S.A.
KENR5809-03
Octobe 2012
Page 1 of 2
COMPONENT LOCATION
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator Gp - Pilot 355-9981 1 E-1
Accumulator. Gp - Ride Control 353-7057 2 E-2
Cylinder Gp - Lift 349-2514
349-2515
(LH)
(RH)
3
E-2
Cylinder Gp - Tilt
Lift
Tilt
Cylinder Gp - Tilt - Logger (Atch)
(966 Standard)
(972 Standard)
Cylinder Gp - Tilt - (966 High Lift - Atch)
Tilt - (972 High Lift - Atch)
352-2057
352-2516
354-7410
349-2517
4
E-3
Filter Gp - Pump Case Drain 139-1537
5
E-3
E-3
6
7
Pump Gp - Implement / Steering 319-6309
8
A-9
9
Breather 312-2684
B-8
10
11
C-6
12
13
Tank Gp - Hydraulic Oil 318-8543
15
A-8
Valve Gp - Backpressure 349-8844
14
B-6
Valve Gp - Relief (Auxiliary Function) 272-2334 D-1
16
Valve Gp - Relief (Make-Up - Lift) 234-4869 D-3
17
Valve Gp - Relief (Margin) 331-9022 C-1
18
Valve Gp - Relief (Ride Control) 4T-7581 D-2
D-4
Valve Gp - 2 Function w/ Ride Control
3 Function w/ Ride Control (Atch)
3 Function w/ Ride Control (Logger Atch)
318-8451
323-2252
318-8453
Valve Gp - Shuttle 235-6157 D-2
21
Valve Gp - Solenoid (Anti-Drift) 328-4314
26
27
D-2
Valve Gp - Solenoid (Pressure Reducing) 313-7688
28
D-3
Valve Gp - Dead Engine Lower 112-1817
22
E-4
Cylinder Gp - Steering 319-5045
23
E-6
Pump Gp - Steering 320-0467
296-5270
344-7391
24
C-5
Pump Gp - Secondary Steering Pump/Motor (Attch) 320-6394
25
E-7
Accumulator - Pilot 306-4025
D-5
Valve Gp - Backpressure 6E-5278 E-6
E-7
E-7
D-5
Sensor Gp - Pressure - Steering (Atch)
Sensor Gp - Pressure - Steering (Atch)
29
Valve Gp - Check - Redundant Steering Pilot 6E-4701
30
31
32
33
34
35
36
Implement System
Steering System
352-2057
Valve Gp - Relief (Load Sense) 235-6160 C-4
19
Valve Gp - Relief (Tilt) 332-1985 D-3
20
Valve Gp - Relief (Tilt - Logger Atch) 332-1986 D-3
COMPONENT LOCATION
Page 2 of 2
Valve Gp - Check - Sec. Steering (Atch) 321-7897 E-7
Valve Gp - Relief - Steering 326-4902 E-6
Valve Gp - Steering 324-0780 E-5
Cooler - Hydraulic Oil - Standard 349-5934 E-9
Accumulator - Brake 198-9841 D-9
Cooler - Hydraulic Oil - High Ambience (Atch) 349-5935 E-9
Filter Gp - Kidney Loop 295-6259 B-8
Motor Gp - Fan 350-7075 D-9
Pump Gp - Fan 352-4500
37
B-9
Valve Gp - Charge (Fan Drive and Brake) 331-6013
38
C-9
Valve Gp - Check (Filter Anti-Drainback) 175-0447
39
B-8
Valve Gp - Cooler Bypass 244-1426
40
E-9
Valve Gp - Park Brake 349-4389
41
D-8
Actuator As - Park Brake 154-8042
42
E-7
Accumulator Gp - Brake Charge 220-2726
43
D-9
44
45
Sensor Gp - Park Brake Pressure
296-5270 D-9
Sensor Gp - Brake Accumulator Pressure
296-5270 D-8
46
47
Valve Gp - Output Pressure 210-5587
48
D-7
Cylinder Gp - Quick Coupler (Atch) 311-1463
49
B-4
Valve Gp - Quick Coupler (Atch) 321-8473
50
B-2
Orifice Gp - (Atch) 168-4988
51
Valve Gp - Sampling Port 8C-3446 D-9
52
53
54
B-3
Quick Coupler (Attachment)
Brake System
Fan / Brake System
55
56
57
58
59
60
61
Pump Gp - Transmission 241-8686 C-6
Valve Gp - Axle Oil Cooler Divider 237-8180 E-9
Valve Gp - Cold Start (Atch) 332-1166 B-9
Miscellaneous
62
Valve Gp - Power Control 286-8970 C-5
Steering System
Description
Part
Number
Machine
Location Location
Schematic
TAP LOCATION
Tap Number Description
Schematic
Location
Front Brake Pressure
Rear Brake Pressure
Park Brake Pressure
Fan Pump Pilot Pressure
Fan Pump Load Sense
Implemt/Redundant Steering Pilot Supply
Primary Steering Pilot Supply
Brake Accumulator
Steering Pump Discharge
Steering Pump Load Sense
Implement Pump Discharge
Implement Pump Load Sense
Fluid Sampling Port
Tap Location
Pressure and Sampling
B D-7
C D-7
D E-7
G1 C-9
G2 B-9
G3 D-1
G4 D-5
G5 D-9
G6 C-8
G7 E-4
G8 D-5
G9 C-4
SOS D-9
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: 315-6598, CHANGE: 05, VERSION: -
MEDIA NUMBER: KENR5809-03
THIS SCHEMATIC IS FOR THE 966K AND 972K WHEEL LOADER HYDRAULIC SYSTEM
A
B
C
D
E
12345678
9
A
B
C
D
E
12345678
9
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
BRAKE COOLING CIRCUIT
IMPLEMENT PUMP CIRCUIT
TRANSMISSION PUMP OUTPUT
STEERING CIRCUIT
FAN PUMP CIRCUIT
SUPPLY LINE
AUXILIARY CIRCUIT
LIFT CIRCUIT
DRAIN / RETURN LINE
IMPLEMENT AND REDUNTANT STEERING PILOT CIRCUIT
QUICK COUPLER CIRCUIT
TILT CIRCUIT
BRAKE CIRCUIT
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
ELECTRICAL CIRCUITS
G6
G8
G5
G4
G9
G7
G3
G1
G2
SOS
D
B
C
T
P
FP RP
RT
FT
S
L
B
X
S
B
L
AXLE
RESERVIOR
E16 E14
E15
E17
E13
P
T
A
B
LS
D
S1
S2
S
P
LS
L
A
PS
PI
S
E2
T
P
C
GP
E23
(32) PUMP
STEERING
320-0467
(62) VALVE GP
POWER CONTROL
286-8970
(12) PUMP GP
IMPLEMENT
319-6309
(36) VALVE GP
CHECK
6E-4701
(29) ACCUMULATOR
PILOT
275-7875
(33) SENSOR
PRESSURE
344-7391
(37) VALVE GP
CHECK
321-7897
(31) MOTOR GP
SECONDARY STEERING PUMP
320-6394
(60) VALVE GP
AXLE OIL
COOLER DIVIDER
237-8180
(50) VALVE GP
COOLER BYPASS
244-1426
(41) COOLER
HYD OIL
349-5934
(52) VALVE GP
SAMPLING PORT
8C-3446
(44) MOTOR GP
FAN
350-7075
(47) SENSOR GP
PARK BRAKE PRESS
296-5270
(51) VALVE GP
PARK BRAKE
349-4389
(48) VALVE GP
FAN DRIVE AND
BRAKE CHARGE
331-6013
(45) PUMP GP
FAN
352-4500
(43) FILTER GP
HIGH PRESS
295-6259
(11) FILTER GP
CASE DRAIN
139-1537
(3) BREATHER
312-2684
(13) TANK GP
HYDRAULIC
318-8543
(46) SENSOR
PRESSURE
BRAKE ACCUM
296-5270
(17) VALVE GP
BACKPRESSURE
349-8844
T
P
C
E24
(61) VALVE GP
COLD START
332-1166
(59) PUMP GP
TRANSMISSION
241-8686
(28) VALVE GP
PRESSURE
REDUCING
313-7668
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(39) VALVE GP
STEERING
324-0780
(38) VALVE GP
STEERING RELIEF
326-4902
(38) VALVE GP
STEERING
RELIEF
326-4902
(35) VALVE GP
BACKPRESSURE
6E-5278
PSG
PS
A1
A2
T
LS
F
P1
SP
P2
PGP
E1
(49) VALVE GP - CHECK
FILTER ANTI-DRAINBACK
175-0447
(30) CYLINDER GP
STEERING
319-5045
(40) ACCUM
BRAKE
198-9841
(34) SENSOR
PRESSURE
296-5270
(42) COOLER
HYD OIL
349-5935
QUICK COUPLER SUPPLY
IMPLEMENT VALVE DRAIN
FRONT AXLE OIL COOLER SUPPLY
IMPLEMENT PUMP LOAD SENSE
IMPLEMENT AND REDUNDANT STEERING PILOT
IMPLEMENT PUMP DISCHARGE
IMPLEMENT RETURN
AXLE OIL COOLER FRONT AXLE RETURN
PORT B
LEVER FORWARD,
RIGHT HAND LINE ON BOOM
PORT A
LEVER REARWARD
LEFT HAND LINE ON BOOM
NOTE A
AXLE
RESERVIOR
NOTE
A: RESOLVER OMITTED FROM LSAT SECTION IN THE
VALVE STACK UNLESS AXLE OIL COOLING
ATTACHMENT IS USED.
RACK
BACK
DUMP
RACK
BACK
HOLD
DUMP
RAISE
LOWER/FLOAT
RAISE
HOLD
LOWER
FLOAT
PORT B
E11
E12
E21
E22
E3
E7
E10
E8
E4
E9
E5
E6
PORT A
HOLD
PORT B
PORT A
T
P
(1) ACCUMULATOR
PILOT
355-9981
(2) ACCUMULATOR
RIDE CONTROL
353-7057
(4) CYLINDER GP
LIFT - RH
349-2514
(5) CYLINDER GP
LIFT - LH
349-2515
(9) CYLINDER GP - TILT
354-7410 (HIGH LIFT ATCH 972)
(7) CYLINDER GP - TILT
352-2057 (STANDARD 972)
(10) CYLINDER GP - TILT
352-2057 (LOGGER ATCH 966)
(8) CYLINDER GP - TILT
349-2517 (HIGH LIFT ATCH 966)
(6) CYLINDER GP - TILT
349-2516 (STANDARD 966)
(16) VALVE GP - IMPLEMENT
318-8453
(15) VALVE GP - IMPLEMENT
323-2252
(14) VALVE GP - IMPLEMENT
318-8451
(56) CYLINDER GP
QUICK COUPLER
311-1463
(57) VALVE GP
QUICK COUPLER
321-8473
(27) VALVE GP
ANTI-DRIFT
328-4314
(9) VALVE GP
RELIEF (TILT)
332-1985
(25) VALVE GP
RELIEF (TILT)
(LOGGER ATCH)
332-1986
(21) VALVE GP
MAKE UP (LIFT)
234-4869
(20) VALVE GP
LOAD SENSE
RELIEF
235-6160
(23) VALVE GP
RELIEF
(RIDE CONTROL)
4T-7581
(26) VALVE GP
SHUTTLE
235-6157
(19) VALVE GP
RELIEF
(AUX FUNCT)
272-2334
(22) VALVE GP
MARGIN RELIEF
331-9022
(18) VALVE GP
MANUAL LOWER
112-1817
E18
E20
E19
L
UL
P
T
(58) ORIFICE
168-4988
(54) ACCUM
BRAKE CHARGE
220-2726
(38) VALVE GP
STEERING RELIEF
326-4902
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(30) CYLINDER GP
STEERING
319-5045
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(18) VALVE GP
MANUAL LOWER
112-1817
(18) VALVE GP
MANUAL LOWER
112-1817
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(28) VALVE GP
PRESSURE REDUCING
313-7688
(24) VALVE GP
RELIEF (TILT)
332-1985
(27) VALVE GP
ANTI-DRIFT
328-4314
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(28) VALVE GP
PRESSURE
REDUCING
313-7688
(27) VALVE GP
ANTI-DRIFT
328-4314
(19) VALVE GP
RELIEF
(AUX FUNCT)
272-2334
(56) CYLINDER GP
QUICK COUPLER
311-1463
SOLENOID VALVE REFERENCE
SOLENOID NAME SOLENOID LOCATION
E1 DEMAND SPEED FAN SOLENOID FAN / BRAKE VALVE
E2 PARK BRAKE SOLENOID ELECTROHYDRAULIC PARK BRAKE VALVE
E3 LOWER SOLENOID IMPLEMENT VALVE - LIFT
E4 RAISE SOLENOID IMPLEMENT VALVE - LIFT
E5 RIDE CONTROL BALANCE SOLENOID IMPLEMENT VALVE - RIDE CONTROL
E6 RIDE CONTROL HEAD END CHECK SOLENOID IMPLEMENT VALVE - RIDE CONTROL
E7 RIDE CONTROL ROD END CHECK SOLENOID IMPLEMENT VALVE - RIDE CONTROL
E8 DUMP SOLENOID IMPLEMENT VALVE - TILT
E9 RACK BACK SOLENOID IMPLEMENT VALVE - TILT
E10 IMPLEMENT PILOT SUPPORT SOLENOID IMPLEMENT VALVE
E11 3RD FUNCTION PORT A SOLENOID IMPLEMENT VALVE - 3RD FUNCTION
E12 3RD FUNCTION PORT B SOLENOID IMPLEMENT VALVE - 3RD FUNCTION
E13 RIGHT PRIMARY STEERING SOLENOID STEERING VALVE
E14 RIGHT REDUNDANT STEERING SOLENOID STEERING VALVE
E15 LEFT PRIMARY STEERING SOLENOID STEERING VALVE
E16 LEFT REDUNDANT STEERING SOLENOID STEERING VALVE
E17 PRIMARY STEERING PILOT SUPPLY SOLENOID STEERING VALVE
E18 ENGAGE SOLENOID QUICK COUPLER VALVE
E19 DISENGAGE SOLENOID QUICK COUPLER VALVE
E20 ENABLE SOLENOID QUICK COUPLER VALVE
E21 LOWER ANTI-DRIFT SOLENOID IMPLEMENT VALVE - LIFT
E22 DUMP ANTI-DRIFT SOLENOID IMPLEMENT VALVE - TILT
E23 IMPLEMENT PUMP TORQUE LIMITER SOLENOID POWER CONTROL VALVE
E24 FAN BYPASS SOLENOID COLD START VALVE ATTACHMENT
REAR AXLE
(55) VALVE GP
OUTPUT
PRESSURE
210-5587
NC
NO
C
C
TO
TRANSMISSION
CONTROL
TO
BRAKE
LIGHTS
APPLY
RELEASE
(53) ACTUATOR AS
PARK BRAKE
154-8042
DIFFERENTIAL
OIL TEMP
WARNING
FRONT AXLE
DIFFERENTIAL
OIL TEMP
WARNING
TAP LOCATION
G8
G1
G6
SOS
G4
G7
G9
C
B
G5
VIEW ALL CALLOUTS

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