INTERACTIVE SCHEMATIC

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 RENR9003-04
March 2011

12M and 120M Motor Grader

Hydraulic System
12M: 120M:
R9B1-UP R9A1-UP
B9F1-UP B9C1-UP
B9R1-UP R9C1-UP
B9N1-UP
B9W1-UP
D9W1-UP

Volume 1 of 2: Service Brakes / Implement / Steering Circuits

Volume 2 of 2: All Wheel Drive

© 2011 Caterpillar All Rights Reserved Printed in U.S.A.

COMPONENT LOCATION
Volume 1 of 2, Page 1 of 2
Part Schematic Machine
Description
Number Location Location
Accumulator Gp - Blade Cushion 219-7265 D-5 1
Accumulator Gp - Brake 249-3860 B-2 2
Breather Assembly 9R-9925 B-8 3
Control Gp - Brake Pedal 308-9523 E-1 4
Cylinder Gp - Articulation 247-0096 D-6 5
Cylinder Gp - Blade Lift 270-7534 D-5 6
Cylinder Gp - Blade Lift 270-7534 D-4 7
Cylinder Gp - Blade Tip 131-3191 F-3 8
Cylinder Gp - Center Shift 262-1907 F-4 9
Cylinder Gp - LH Steering 276-5682
D-3 10
(AWD) 262-5766
Cylinder Gp - RH Steering 255-8715
E-2 12
(AWD) 262-5766
Cylinder Gp - Ripper Lift 113-7754 D-7 11
Cylinder Gp - Side Shift 260-6502 F-4 13
Cylinder Gp - Wheel Lean 249-5299 F-6 14
Filter Gp - Pilot 191-9784 B-4 15
Filter Gp - Return 249-2307 A-8 16
Lock Gp - Center Shift 298-2600 D-4 17
Manifold Gp - Control Blade Cushion 253-1320 D-5 18
Manifold Gp - Pilot Shutoff Solenoid 263-1790 B-5 19
Motor Gp - Circle Drive 105-3196 F-5 20
Motor Gp - Fan 250-9831 A-3 21
Pump Gp - Fan / Brake 250-8337 B-7 22
Pump Gp - Implement / Steering 266-0330 B-6 23
Pump Gp - Secondary Steer 273-8714 A-6 24
Screen - Fan / Brake Control 6E-5066 B-3 25
Screen - Implement Control Valve (Front) 250-1420 E-3 26
Screen - Implement Control Valve (Rear) 250-1420 C-4 27
COMPONENT LOCATION
Volume 1 of 2, Page 2 of 2
Part Schematic Machine
Description
Number Location Location
Screen - Steer Pilot Manifold Valve 6E-5066 C-2 28
Sensor Gp - Pressure (Brake Accumulators) 237-0957 B-3 29
Sensor Gp - Pressure (Secondary Steering) 237-0957 B-6 30
Switch As - Pressure (Pilot Filter Bypass) 7X-8549 B-5 31
Swivel - Blade 260-6502 F-4 32
Tank Gp - Hydraulic Oil 241-3867 B-7 33
Valve - Shuttle (Load Signal Resolver) 6R-7605 B-3 34
Valve Gp - Check (E) 193-9230 B-5 35
Valve Gp - Check (Implement / Steer) 255-3631 B-6 36
Valve Gp - Check (Secondary Steer) 9T-1013 A-5 37
Valve Gp - Cooler Bypass 266-1595 A-4 38
Valve Gp - Fan / Brake Control 251-8256 A-3 39
Valve Gp - Implement Control (Front) (5-BANK) 248-6168
(6-BANK) 249-7295 F-2 40
(7-BANK) 249-5328
Valve Gp - Implement Control (Rear) (4-BANK) 249-7298
C-4 41
(6-BANK) 291-9517
Valve Gp - Relief (Secondary Steer) 9T-8071 A-5 42
Valve Gp - Steering Control 308-0934 D-2 43
Valve Gp - Steering Pilot Manifold 254-3415 C-1 44
COMPONENT LOCATION
Volume 2 of 2 - ALL WHEEL DRIVE
Part Schematic Machine
Description
Number Location Location
Filter Gp - Charge (Front Pump) 196-1803 C-5 1
Filter Gp - Charge (Rear Pump) 196-1803 D-3 2
Manifold Gp - Control (AWD) 294-1109 E-5 3
Motor Gp - LH Front AWD 287-1893 E-7 4
Motor Gp - RH Front AWD 287-1893 E-2 5
Pump Gp - All Wheel Drive 246-4490 C-6 6
Sensor Gp - Pressure (LT AWD Sensor Control) 214-6863 D-5 7
Sensor Gp - Pressure (RT AWD Sensor Control) 214-6863 E-5 8
Sensor Gp - Temperature 264-4297 C-1 9
Switch As - Pressure (Oil Filter Bypass) 134-0404 D-3 10
Switch As - Pressure (Oil Filter Bypass) 134-3404 C-5 11
Valve Gp - Thermal Bypass 188-8726 C-2 12
TAP LOCATION
Volume 1 of 2

Tap Schematic
Number Description Location
AA Implement / Steering Pump Load Sense B-6
BB Implement / Steering Pump Pressure B-5
CC Pilot Supply Pressure B-5
DD Fan Motor Supply Pressure A-3
EE Service Brake LH Pressure D-1
FF Service Brake RH Pressure D-1
SOS 1 Hydraulic Oil Sampling B-5
SOS 2 Hydraulic Oil Sampling B-5
TAP LOCATION
Volume 2 of 2 - ALL WHEEL DRIVE

Tap Schematic
Description
Number Location
A1 LH Motor Forward Pressure E-4
A2 RH Motor Reverse Pressure E-4
B1 RH Motor Forward Pressure E-6
B2 LH Motor Reverse Pressure E-6
LL Front Charge Pump Pressure C-5
NN Rear Charge Pump Pressure C-4
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
PLOW ANGLE CYLINDER PLOW LIFT CYLINDER (9) CYLINDER GP
(20) MOTOR GP CENTER SHIFT (8) CYLINDER GP (40) VALVE GP
(14) CYLINDER GP CIRCLE DRIVE BLADE TIP
262-1908 IMPLEMENT
WHEEL LEAN 105-3196 131-7191 CONTROL
SCARIFIER 249-5299
(13) CYLINDER GP (FRONT)
CYLINDERS NOT SIDE SHIFT 248-6168 (5-BANK)
SHOWN 249-4116 249-7295 (6-BANK) SCARIFIER HYDRAULIC CIRCUIT COLOR DESCRIPTIONS

(32) SWIVEL 249-5328 (7-BANK) PLOW IMPLEMENT AND STEERING PUMP OUTPUT
SECONDARY STEERING PUMP OUTPUT

BLADE CENTERSHIFT LOCK CONTROL CIRCUIT

F
F FAN AND BRAKE PUMP OUTPUT
260-6502 CENTERSHIFT CYLINDER CONTROL CIRCUIT
SIDE SHIFT CYLINDER CONTROL CIRCUIT
B A B A B A B A B A B A B A SUPPLY LINE
DRAIN / RETURN LINE
STEERING CYLINDER CONTROL CIRCUIT
BLADE TIP CYLINDER CONTROL CIRCUIT
PILOT SHUTOFF CIRCUIT
CIRCLE DRIVE MOTOR CONTROL CIRCUIT
IMPLEMENT AND STEERING LOAD SENSE CIRCUITS
BLADE LIFT CYLINDER CONTROL CIRCUITS
WHEEL LEAN CYLINDER CONTROL CIRCUIT
ARTICULATION CYLINDER CONTROL CIRCUIT
SERVICE BRAKE CONTROL CIRCUIT
RIPPER LIFT CYLINDER CONTROL CIRCUIT
SNOW WING AND PLOW CYLINDER CONTROL CIRCUITS

)(

(4) CONTROL GP
BRAKE PEDAL
308-9523
E E
(12) CYLINDER GP
(26) SCREEN RH STEERING
PLOW ANGLE (7-BANK) PLOW LIFT (7-BANK) WHEEL LEAN CIRCLE DRIVE CENTER SHIFT SIDE SHIFT BLADE TIP FRONT IMPLEMENT 255-8715
OR OR CONTROL VALVE 262-5766 (AWD)
SCARIFIER (6-BANK) REMOVED (6-BANK) 250-1420
(17) LOCK GP
CENTER SHIFT
298-2600

(5) CYLINDER GP (6) CYLINDER GP

ARTICULATE BLADE LIFT (LH) (10) CYLINDER GP
(11) CYLINDER GP 262-7758 270-7534 LH STEERING
(7) CYLINDER GP (43) VALVE GP EE
RIPPER LIFT BLADE LIFT (RH) 255-8715
(1) ACCUMULATOR CL STEERING
113-7754 (1) ACCUMULATOR 270-7534 262-5766 (AWD) CR
BLADE CUSHION CONTROL
BLADE CUSHION
219-7265 308-0934
219-7265
FF
CENTER SHIFT
BLADE BLADE LOCK
CUSHION CUSHION
ATTCH ATTCH
WING TILT CYLINDER WING LIFT CYLINDER
D D
LE

(41) VALVE GP L
249-7298 (4-BANK)
(18) MANIFOLD GP (18) MANIFOLD GP 291-9517 (6-BANK)
R
BLADE CUSHION BLADE CUSHION RE
253-1320 253-1320
B A B A B A B A B A B A (44) VALVE GP
STEERING PILOT
MANIFOLD
254-3415

C C
)( (28) SCREEN
Ps (STEER PILOT
MANIFOLD
VALVE)
6E-5066
EF

Ts

WING TILT (6-BANK) WING LIFT (6-BANK) RIPPER ARTICULATION BLADE LIFT (LEFT) BLADE LIFT (RIGHT)
(36) VALVE GP (29) SENSOR GP P
(3) BREATHER AS LS T
9R-9925
(33) TANK GP AA CHECK (IMP/STEER) PRESSURE
HYDRAULIC 255-3631 BRAKE ACC
(27) SCREEN (34) VALVE SHUTTLE
241-3867 237-0957
REAR IMPLEMENT
(22) PUMP GP (LOAD SIGNAL RESOLVER)
CONTROL VALVE
FAN/BRAKE 6R-7605
(23) PUMP GP 250-1420
250-8337 IMPLEMENT/ BB SOS
2 CC
STEERING
266-0330
(30) SENSOR GP PS
B PRESSURE B
(25) SCREEN
SEC STEERING
237-0957 (FAN/BRAKE
LS CONTROL)
SOS
1
6E-5066

A1

(2) ACCUMULATOR GP
(19) MANIFOLD GP CE BRAKE
PILOT SHUTOFF (15) FILTER GP P 249-3860 LINE PATTERNS
(16) FILTER GP SOLENOID PILOT 249-3862 (CE)
RETURN 263-1790 191-9784 Pressure Line
(31) SWITCH AS
249-2307 (35) VALVE GP A2 Pilot / Load Sensing Pressure
(37) VALVE GP PRESSURE
CHECK(E) PILOT FILTER Drain / Return Lines
CHECK
193-9230 BYPASS
(SEC STEER) Component Group

TO AWD PUMP 9T-1013 7X-8549

FAN/BRAKE PUMP Attachment
LOC VOL 2 SEC B-1

(38) VALVE GP T Air Line

TO AWD PUMP IMPLEMENT/ DD (21) MOTOR GP

COOLER FAN CALLOUTS
A LOC VOL 2 SEC B-1 STEERING (42) VALVE GP
BYPASS
(39) VALVE GP A
RELIEF 250-9831 FAN/BRAKE YY Taps (Pressure, Sampling,Sensor) by letter
266-1595
(SEC STEER) CONTROL
9T-8071 251-8256
THIS SCHEMATIC IS FOR THE 12M AND 120M MOTOR GRADER HYDRAULIC SYSTEM
VOLUME 1 of 2: SERVICE BRAKES / IMPLEMENT / STEERING CIRCUITS
MEDIA NUMBER: RENR9003-04
(24) PUMP GP SCHEMATIC PART NUMBER: 264-5729, CHANGE: 03, VERSION: -
SECONDARY Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
FROM AWD PUMPS FROM AWD MOTORS
STEER LOC VOL 2 SEC B-1
in neutral and with parking brake set.
LOC VOL 2 SEC C-1 Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
273-8714
8 7 6 5 4 3 2 1
 8 7 6 5 4 3 2 1

F F

(8) SENSOR GP
PRESSURE
AWD SENSOR CONT
RIGHT
(4) MOTOR GP
214-6863
LH FRONT AWD
287-1893
)( (3) MANIFOLD GP
L CONTROL (AWD) (5) MOTOR GP
294-1109 RH FRONT AWD
A PS2 C2 MR
287-1893
RIGHT
CONT
E L
RIGHT
B2 A2 A
E E
B2 FWD REV A2
B2G A2G
E
U
B2 A2
X T1 T
B1G A1G
B1 A1
B1 A1
MAX MIN REV FWD
LEFT
X U
B1 CONT A1

B LEFT
(7) SENSOR GP
PRESSURE max min
AWD SENSOR CONT
LEFT PS1 C1 ML P B
214-6863
)(

D D

(10) SWITCH AS
PRESSURE
(2) FILTER GP
OIL FILTER (12) VALVE GP
CHARGE
BYPASS THERMAL BYPASS
REAR PUMP
134-0404 188-8726
196-1803

(11) SWITCH AS
(1) FILTER GP
PRESSURE
CHARGE
OIL FILTER
FRONT PUMP
BYPASS
196-1803
134-0404
(6) PUMP GP
ALL WHEEL DRIVE
246-4490

F F
X LL X NN
P(S) L S(P) Mp P(S) L S(P) Mp B B C
C TO COOLER INLET
LOC VOL 1 SEC A-4

(9) SENSOR GP
TEMPERATURE
264-4297

FRONT REAR
FRONT REAR CHARGE CHARGE
PISTON PISTON PUMP PUMP
PUMP PUMP

Ms U Ms U A A

Z Z
Y Y FROM TANK B
B
LOC VOL 1 SEC A-8

FROM TANK
LOC VOL 1 SEC A-8

T T
TO RTN MANIFOLD
LOC VOL 1 SEC A-6

LINE PATTERNS
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS Pressure Line
FRONT CHARGE PUMP OUTPUT
REAR AWD PUMP AND RIGHT MOTOR CONTROL CIRCUIT
Pilot / Load Sensing Pressure
FRONT AWD PUMP AND LEFT MOTOR CONTROL CIRCUIT
REAR CHARGE PUMP OUTPUT
Drain / Return Lines
FRONT WHEEL BRAKE CONTROL CIRCUIT
Component Group
SUPPLY LINE
DRAIN / RETURN LINE
Attachment

Air Line

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

THIS SCHEMATIC IS FOR THE 12M AND 120M MOTOR GRADER HYDRAULIC SYSTEM
VOLUME 2 of 2 : ALL WHEEL DRIVE
MEDIA NUMBER: RENR9003-04
SCHEMATIC PART NUMBER: 264-5729, CHANGE: 03, VERSION: -
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.

8 7 6 5 4 3 2 1
MACHINE COMPONENT LOCATIONS
VIEW ALL CALLOUTS
42 22 23 3 16 33 37 24 5 8 28 44 43 17 13 9 7 18 34 1 10
19
30
36

31 26
11 40
15
21

38

39 29 25 2 5 4 41 27 34 6 32 20 12 14

36 38 22 23 16 3 33 43 28 44 17 27 41 34 6 7 1 18 34
19
40
30
26
37
21

11

31 15 42 29 25 39 24 2 5 4 8 13 9 32 20 10 12 14
MACHINE COMPONENT LOCATIONS - ALL WHEEL DRIVE
VIEW ALL CALLOUTS

11

10 8
2 7
1 9 12 6 5 3

11

10 8
5
2 7
1 12 6 4 3
SERVICE BRAKES
VIEW ALL CALLOUTS

EE (LH) FF (RH)

LH VIEW
IMPLEMENT / STEERING CIRCUIT
VIEW ALL CALLOUTS

33 19

23

SOS
1
CC
AA BB
SOS
2

FW
D

19
15

15
FAN / BRAKE CONTROL
VIEW ALL CALLOUTS

38

DD
ALL WHEEL DRIVE PUMP GROUP
REAR PISTON FRONT PISTON VIEW ALL CALLOUTS

PUMP (RS) PUMP (LS)

NN 6 6
FRONT CHARGE
6
PUMP (LS)

REAR CHARGE
PUMP (RS)
6

LL

FWD

12
AWD CHARGE FILTERS
VIEW ALL CALLOUTS

11 2 10 1 9
AWD CONTROL MANIFOLD
VIEW ALL CALLOUTS

CONTROL RT CONTROL LT
SOLENOID SOLENOID
RIGHT REV LEFT FWD
SOLENOID SOLENOID
RIGHT FWD LEFT REV
SOLENOID SOLENOID

8 7

PS2 PS1
B2G A2G A1G B1G

A A

B2 A2 3 A1 B1

B2 B1

A2 A1

VIEW A-A