INTERACTIVE SCHEMATIC
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Hydraulic System
928G Wheel loader
DJD1-UP
WLG1-UP
©
2008 Caterpillar, All Rights Reserved
Printed in U.S.A.
KENR8950
May 2008
COMPONENT LOCATION
Description
Part
Number
928G
Machine
Location
Schematic
Location
Accumulator Gp - Brake 140-9251 1 C-7
Accumulator Gp - Pilot 243-4398 2 D-1
Accumulator Gp - Ride Control 223-9698 3 C-2
Cooler As - Dual Disc Axle Oil 205-3652 4 B-8
Cooler - Heavy Duty 239-7395
Cooler - Standard 239-7394
Cylinder Gp - LH Steering 125-0374 6
F-8
Cylinder Gp - Lift 119-1060 7 A-3
Cylinder Gp - RH Steering 125-0373 8 F-7
Cylinder Gp - Tilt 118-8105 9 A-4
Filter Gp - Filter Element 126-1818 209-3149 10 A-8
Manifold 209-0787 11 D-6
Motor Gp - Axle Oil Cooler 205-5268 12 A-8
Motor Gp - Rad / Hydr-Fan 205-3669
Motor Gp - Reversing Fan 205-3668
Orifice 1 114-0441 14
B-3
Orifice 2 8C-0564 15
C-3 , C-5
Pump Gp - Brake/ Fan/ Filter/ Oil Clr 262-2875 16 B-6
Pump Gp - HMU/ Thermal Bleed 223-2223 17 E-7
Pump Gp - Implmnt / Strng 119-7698 18 C-7
Pump Gp - Secondary Str 205-5266 19 D-7
Screen As 247-8298 20 B-7
Sensor Gp - Pressure Brake 224-4536 21 B-6
Sensor Gp - Transmission Neutralizer 290-5825 22 C-8
Switch As - Axle Cooler Pressure 3E-7690 23 B-8
Switch As - Secondary Steering 230-5771 24 D-7
Tank Gp - Hydraulic 205-5408 25 A-6
Valve As - Foot Brake 144-8521 26 C-7
Valve Gp - Ball, Dead Engine Lower 112-1817 27 B-3
Valve Gp - Check 9T-1013 28 E-7 , C-1
Valve Gp - Implement, 2 Section 133-4234
Valve Gp - Implement, 3 Section 133-4235
Valve Gp - Implement, 4 Section 150-1954
Valve Gp - Pilot Shutoff 233-7133 30
D-2
Valve Gp - Pilot, 2 Single Function Levers 201-3360
Valve Gp - Pilot, 3 Single Function Levers
201-3362
Valve Gp - Pilot, Joystick 201-3359
Valve Gp - Pilot, Joystick & 2 Aux 203-3363
Valve Gp - Pilot, Joystick & Aux 201-3361
Valve Gp - Press Reducing 185-5209 32
D-2
Valve Gp - Relief 1 186-0905 33 B-4
Valve Gp - Relief 2 186-0913 34 B-4
Valve Gp - Relief 3 185-7708 35 B-3
Valve Gp - Relief 4 251-0907 36 D-7
Valve Gp - Relief, Main 108-6428 33 B-5
Valve Gp - Shutoff, Hydraulic Drain 6V-7238 38 D-6
Valve Gp - Shuttle, Ride Control 141-1481 39 C-1
Valve Gp - Solenoid Ride Control Valve 297-1209 40 C-2
Note : Refer to Parts Manual for your specific machine
29
29
29
31
5
13
B-8
B-7
B-4
B-5
B-3
D-4
TAP LOCATION
Tap Description
Schematic
Location
PT1 Implement Pump Discharge Pressure D-6
PT2 Steering Pump Discharge Pressure D-2
PT3 Pilot Supply Pressure D-2
PT4 Front Brake Pressure C-8
PT5 Rear Axle Cooler Circuit Pressure B-8
PT6 Hydraulic Oil Sampling Port A-8
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
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
YY
THIS SCHEMATIC IS FOR THE 928G WHEEL LOADER
PART NUMBER: 203-4656, CHANGE: 03, VERSION: (-)
Components are shown installed on a fully operable machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
DRAIN / RETURN LINE
LINES GROUP COLOR DESCRIPTIONS
STEERING / PILOT PUMP OUTPUT
IMPLEMENT PUMP
STEERING CIRCUIT
PILOT
SIXTH FUNCTION
AXLE OIL
FAN / BRAKE PUMP CIRCUIT
SUPPLY LINE
LOAD SENSING
THIRD FUNCTION
ELECTRICAL WIRES
LIFT CYLINDERS
FOURTH FUNCTION
TILT CYLINDERS
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
REVERSING FAN OPTION
N1
PT6
T
LS
P
M
FROM CONTROLLER
TO REAR BRAKES
TO FRONT BRAKES
PT4
AXLE OIL
TO THIRD FUNCTION
DUMP
LOWER /
FLOAT
RAISE
WIRED TO CONTROLLER
RACKBACK
PT1
PT2
PT3
S4
PT5
O
P
T
A1
A2
EF
S1
BACK
FORWARD
TO FOURTH FUNCTION
(25) TANK GP
HYDRAULIC
205-5408
(18) PUMP GP
IMP / STR
119-7698
(29) VALVE GP
IMPLEMENT 4 SECTION
150-1954
(29) VALVE GP
IMPLEMENT 3 SECTION
133-4235
(29) VALVE GP
IMPLEMENT 2 SECTION
133-4234
(32) VALVE GP
PRESS. RED
185-5209
(26) VALVE AS
FOOT BRAKE
144-8521
(28) VALVE GP
CHECK
9T-1013
(36) VALVE GP
RELIEF 4
251-0907
(31) VALVE GP
PILOT
2 SINGLE FUNCTION LEVERS : 201-3360
3 SINGLE FUNCTION LEVERS : 201-3362
JOYSTICK : 201-3359
JOYSTICK / AUX : 201-3361
JOYSTICK / 2 AUX : 203-3363
(40) VALVE GP
SOLENOID
RIDE CONTROL
297-1209
(7) CYLINDER GP
LIFT
119-1060
(9) CYLINDER GP
TILT
118-8105
(11) MANIFOLD
209-0787
(2) ACCUMULATOR GP
PILOT
243-4398
(12) MOTOR GP
AXLE OIL CLR
205-5268
(5) COOLER
STANDARD: 239-7394
HEAVY DUTY: 239-7395
(17) PUMP GP
HMU
W/ THERMAL BLEED
223-2223
(19) PUMP GP
SUPP STR
205-5266
(6) CYLINDER GP
LH STEERING
125-0374
(1) ACCUMULATOR GP
BRAKE
140-9251
(3) ACCUMULATOR GP
RIDE CONTROL
223-9698
(16) PUMP GP
BRAKE/ FAN/ FILTER
262-2875
(13) MOTOR GP
RAD/ HYDR
205-3669
REVERSING
205-3668
(10) FILTER GP
209-3149
(ELEMENT: 126-1818)
(30) VALVE GP
PILOT SHUTOFF
233-7133
(27) VALVE GP
BALL
DEAD ENG LWR
112-1817
(4) COOLER AS
DUAL DISC AXLE OIL
205-3652
(38) VALVE GP
SHUTOFF
HYDR. DRAIN
6V-7238
(24) SWITCH AS
SEC STR
230-5771
(22) SENSOR GP
XMSSN. NEUTRALIZER
290-5825
(23) SWITCH AS
AXLE CLR
3E-7690
(20) SCREEN AS
247-8298
(21) SENSOR GP
BRAKE
224-4536
(39) VALVE GP
SHUTTLE
RIDE CONTROL
141-1481
(28) VALVE GP
CHECK
9T-1013
(14) ORIFICE 1
114-0441
(8) CYLINDER GP
RH STEERING
125-0373
(35) VALVE GP
RELIEF 3
185-7708
(34) VALVE GP
RELIEF 2
186-0913
(33) VALVE GP
RELIEF 1
186-0905
(33) VALVE GP
RELIEF, MAIN
108-6428
(15) ORIFICE 2
8C-0564
(15) ORIFICE 2
8C-0564
(52) VALVE GP - CONTROL
138-1234
Callout Number
(Machine Location from
Component Locations Table
Component
Name
Part Number
MACHINE COMPONENT LOCATIONS
PT6
PT5
PT4
PT3
PT2
PT1
40
39
38
36
35
34
33
32 31
30
29
28
27
26
25
25
23
22
21
20
19 18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
VIEW ALL CALLOUTS
AXLE OIL COOLING
PT5
23
20
12
4
VIEW ALL CALLOUTSVIEW ALL CALLOUTS
FILTER GP
PT6
10
VIEW ALL CALLOUTS
FOOT BRAKE VALVE
PT4
26 22
VIEW ALL CALLOUTS
MANIFOLD
PT1
38
VIEW ALL CALLOUTS
PILOT PRESS REDUCING VALVE
REAR
VIEW
TOP
VIEW
PT3 PT3PT2 PT2
32
VIEW ALL CALLOUTS
PUMP GP
STEERING / PILOT PUMP
IMPLEMENT PUMP
10
