This schematic shows the hydraulic system for a 140M or 160M motor grader. It displays the components, lines, and connections that make up the system. Lines are color coded based on their function. Component callouts provide identification numbers and locations to reference in the service manual. Taps are labeled for measuring pressure or sampling fluid at key points in the system.

1. INTERACTIVE SCHEMATIC
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These are hyperlinks that can be used to navi-
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located in the top right corner of every machine view page.
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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
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2. Hydraulic System
12M, 140M and 160M Motor Grader
140M:
B9D1-UP
B9M1-UP
B9G1-UP
D9G1-UP
160M:
B9E1-UP
B9L1-UP
B9T1-UP
D9T1-UP
©2012 Caterpillar, All Rights Reserved Printed in U.S.A.
RENR9009-06
August 2012
Volume 1 of 2: Machine Systems
Volume 2 of 2: All Wheel Drive
12M:
B921-UP

3. Volume 1 of 2 - Machine Systems
COMPONENT LOCATION
Description
Part
Number
Schematic
Location
Machine
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 301-4129 E-1 4
Cylinder Gp - Articulation 247-0096 D-6 5
Cylinder Gp - Blade Lift (LH) 262-1900 D-5 6
Cylinder Gp - Blade Lift (RH) 262-1900 D-4 7
Cylinder Gp - Blade Tip 131-7191 F-3 8
Cylinder Gp - Center Shift 262-1907 F-4 9
Cylinder Gp - LH Steering 276-5682
(AWD) 262-5766
Cylinder Gp - RH Steering 276-5681
(AWD) 262-5766
Cylinder Gp - Ripper Lift 113-7754 D-7 11
Cylinder Gp - Side Shift 249-4116 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 236-7296 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
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-5 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
(7-BANK) 249-5328
Valve Gp - Implement Control (Rear) (4-BANK) 249-7298
(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
F-2 40
C-4 41
D-3 10
E-2 12
Sensor As - Temperature (Hydraulic Fan Oil) 264-4297 A-4 45

4. Volume 2 of 2 - All Wheel Drive
COMPONENT LOCATION
Description
Part
Number
Schematic
Location
Machine
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

5. Volume 1 of 2 - Machine Systems
TAP LOCATION
Tap
Number
Description
Schematic
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

6. Volume 2 of 2 - All Wheel Drive
TAP LOCATION
Tap
Number
Description
Schematic
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

7. 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 CONDITIONERPUMP or MOTOR
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVES
PILOT CONTROL SYMBOLSRELEASED 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

8. 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 ColorCircuit Number
Identification
B A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical WirePressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
T

9. THIS SCHEMATIC IS FOR THE 140M & 160M Motor Grader (Volume1)
PART #: 266-1591 CH03 (140M) & 236-8830 CH06 (160M)
Components are shown installed on a fully operable machine with the key and engine
off and transmission shifter in neutral.
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letterYY
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
DRAIN / RETURN LINE
LINES GROUP COLOR DESCRIPTIONS
IMPLEMENT & STEERING PUMP OUTPUT
FAN & BRAKE PUMP OUTPUT
STEERING CYLINDER CONTROL CIRCUIT
SECONDARY STEERING PUMP OUTPUT
SIDE SHIFT CYLINDER CONTROL CIRCUIT
CENTERSHIFT LOCK CONTROL CIRCUIT
SUPPLY LINE
PILOT SHUTOFF CIRCUIT
WHEEL LEAN CYLINDER CONTROL CIRCUIT
CIRCLE DRIVE MOTOR CONTROL CIRCUIT
CENTERSHIFT CYLINDER CONTROL CIRCUIT
ARTICULATION CYLINDER CONTROL CIRCUIT
SERVICE BRAKE CONTROL CIRCUIT
BLADE LIFT CYLINDER CONTROL CIRCUITS
BLADE TIP CYLINDER CONTROL CIRCUIT
IMPLEMENT & STEERING LOAD SENSE CIRCUITS
RIPPER LIFT CYLINDER CONTROL CIRCUIT
SNOW WING & PLOW CYLINDER CONTROL CIRCUITS
BB
CCAA
DD
FF
EE
SOS
2
SOS
1
)(
)(
LS
P
T
A1
PS
A2
FAN/BRAKE PUMP
CENTER SHIFT
LOCK
EF
P LS T
Ts
Ps
LE
RE
L
R
CL CR
(33) TANK GP
HYDRAULIC OIL
241-3867
(3) BREATHER AS
9R-9925
(23) PUMP GP
IMPLEMENT/
STEERING
236-7296
(22) PUMP GP
FAN/BRAKE
250-8337
(24) PUMP GP
SECONDARY
STEER
273-8714
(2) ACCUMULATOR GP
BRAKE
249-3860
(39) VALVE GP
FAN/BRAKE
CONTROL
251-8256
(25) SCREEN
(FAN/BRAKE
CONTROL)
6E-5066
(28) SCREEN
(STEER PILOT
MANIFOLD
VALVE)
6E-5066
(34) VALVE
SHUTTLE
(LOAD SIGNAL RESOLVER)
6R-7605
(44) VALVE GP
STEERING PILOT
MANIFOLD
254-3415
(32) SWIVEL
BLADE
260-6502
(8) CYLINDER GP
BLADE TIP
131-7191
(13) CYLINDER GP
SIDE SHIFT
249-4116
(9) CYLINDER GP
CENTER SHIFT
262-1907
(14) CYLINDER GP
WHEEL LEAN
249-5299
(20) MOTOR GP
CIRCLE DRIVE
105-3196
(7) CYLINDER GP
BLADE LIFT (RH)
262-1900
(6) CYLINDER GP
BLADE LIFT (LH)
262-1900
(5) CYLINDER GP
ARTICULATION
247-0096
IMPLEMENT/
STEERING
BLADE LIFT (LEFT) BLADE LIFT (RIGHT)ARTICULATION
BLADE TIPSIDE SHIFTCENTER SHIFTCIRCLE DRIVEWHEEL LEAN
(17) LOCK GP
CENTER SHIFT
298-2600
(41) VALVE GP
IMPLEMENT CONTROL (REAR)
249-7298 (4-BANK)
291-9517 (6-BANK)
(26) SCREEN
IMPLEMENT
CONTROL VALVE (FRONT)
250-1420
(36) VALVE GP
CHECK (IMP/STEER)
255-3631
(37) VALVE GP
CHECK
(SEC STEER)
9T-1013
(27) SCREEN
IMPLEMENT
CONTROL VALVE
(REAR)
250-1420
(1) ACCUMULATOR
BLADE CUSHION
219-7265
(18) MANIFOLD GP
CONTROL BLADE CUSHION
253-1320
PLOW LIFT (7-BANK)
(16) FILTER GP
RETURN
249-2307
(19) MANIFOLD GP
PILOT SHUTOFF
SOLENOID
263-1790
(15) FILTER GP
PILOT
191-9784
(42) VALVE GP
RELIEF
(SEC STEER)
9T-8071
(35) VALVE GP
CHECK(E)
193-9230
(38) VALVE GP
COOLER
BYPASS
266-1595
(21) MOTOR GP
FAN
250-9831
(4) CONTROL GP
BRAKE PEDAL
301-4129
(43) VALVE GP
STEERING
CONTROL
308-0934
(12) CYLINDER GP
RH STEERING
276-5681
262-5766 (AWD)
(10) CYLINDER GP
LH STEERING
276-5682
262-5766 (AWD)
(40) VALVE GP
IMPLEMENT CONTROL (FRONT)
248-6168 (5-BANK)
249-7295 (6-BANK)SCARIFIER
249-5328 (7-BANK)PLOW
PLOW ANGLE (7-BANK)
RIPPERWING LIFT (6-BANK)WING TILT (6-BANK)
(11) CYLINDER GP
RIPPER LIFT
113-7754
B A B A B A B A B A B A B A
B A B A B A B A B A B A
PLOW LIFT CYLINDERPLOW ANGLE CYLINDER
WING LIFT CYLINDERWING TILT CYLINDER
SCARIFIER (6-BANK)
OR
REMOVED (6-BANK)
OR
SCARIFIER
CYLINDERS NOT
SHOWN
BLADE
CUSHION
ATTCH
BLADE
CUSHION
ATTCH
TO AWD PUMP
TO AWD PUMP
LOC VOL 2 SEC B-1
LOC VOL 2 SEC B-1
FROM AWD MOTORS
LOC VOL 2 SEC C-1
(30) SENSOR GP
PRESSURE
SEC STEERING
237-0957
(29) SENSOR GP-PRESSURE
BRAKE ACC
237-0957
FROM AWD PUMPS
LOC VOL 2 SEC B-1
(31) SWITCH AS
PRESSURE
PILOT FILTER
BYPASS
7X-8549
12345678
A
C
D
E
F
12345678
A
B
C
D
E
F
B
(45) SENSOR AS
TEMPERATURE
(HYDRAULIC FAN OIL)
264-4297

10. DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
FRONT CHARGE PUMP OUTPUT
REAR CHARGE PUMP OUTPUT
REAR AWD PUMP AND RIGHT MOTOR CONTROL CIRCUIT
FRONT AWD PUMP AND LEFT MOTOR CONTROL CIRCUIT
SUPPLY LINE
FRONT WHEEL BRAKE CONTROL CIRCUIT
THIS SCHEMATIC IS FOR THE 140M & 160M Motor Grader (Volume2)
PART #: 266-1591 CH03 (140M) & 236-8830 CH06 (160M)
Components are shown installed on a fully operable machine with the key and engine
off and transmission shifter in neutral.
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letterYY
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
NNLL
(4) MOTOR GP
LH FRONT AWD
287-1893
(5) MOTOR GP
RH FRONT AWD
287-1893
(3) MANIFOLD GP
CONTROL (AWD)
294-1109
(6) PUMP GP
ALL WHEEL DRIVE
246-4490
(1) FILTER GP
CHARGE
FRONT PUMP
196-1803
(2) FILTER GP
CHARGE
(REAR PUMP)
196-1803
(12) VALVE GP
THERMAL BYPASS
188-8726
B2
B1 A1
A2
FROM TANK
U
A
max min
L
B
Z
Y
P(S) L S(P) Mp
F
X
P(S) L S(P) Mp
F
X
B B
U A AU
Z
Y
T
Ms
T
Ms
A
U
B1
B1
C1
T1
B2
B2
C2
ML
A1
A1
MR
T
A2
A2
P
max min
L
B
FROM TANK
TO RTN MANIFOLD
)(
)(
X
E
E
X
LOC VOL 1 SEC A-8
LOC VOL 1 SEC A-8
LOC VOL 1 SEC A-6
B2G
B1G
A2G
A1G
RIGHT
CONT
LEFT
CONT
RIGHT
LEFT
REVFWD
FWDREV
PS2
PS1
(8) SENSOR GP
PRESSURE
(RT AWD SENSOR CONT)
214-6863
(7) SENSOR GP
PRESSURE
LT AWD SENSOR CONT
214-6863
(9) SENSOR GP
TEMPERATURE
264-4297
TO COOLER INLET
LOC VOL 1 SEC A-4
FRONT
PISTON
PUMP
REAR
PISTON
PUMP
FRONT
CHARGE
PUMP
REAR
CHARGE
PUMP
(10) SWITCH AS
PRESSURE
(OIL FILTER BYPASS)
134-0404
(11) SWITCH AS
PRESSURE
(OIL FILTER
BYPASS)
134-0404
12345678
A
C
D
E
F
12345678
A
B
C
D
E
F
B

11. MACHINE COMPONENT LOCATIONS
44
44
43
43
42
42
41
41
40
40
39
39
37
37
36
36
3434
34
34
32
32
31
31
30
30
29
29
28
28
27
27
26
26
25
25
24
24
22
22
21
21
20
20
18
18
17
17
16
16
14
14
13
13
12
12
11
11
10
10
9
9
8
8
7
7
6
6
5
5
5
4
4
3
3
2
2
1
1
VIEW ALL CALLOUTS

12. MACHINE COMPONENT LOCATIONS
12
12
11
11
10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
VIEW ALL CALLOUTS

13. ALL WHEEL DRIVE PUMP GROUP
FWD
NN
LL
12
6 6
VIEW ALL CALLOUTS

14. AWD CHARGE FILTERS
11 10 92 1
VIEW ALL CALLOUTS

15. AWD CONTROL MANIFOLD
B2G A2G A1G B1G
PS2 PS1
P
B2 B1
A2 A1
LEFT REV
SOLENOID
LEFT FWD
SOLENOID
RIGHT REV
SOLENOID
RIGHT FWD
SOLENOID
CONTROL RT
SOLENOID
CONTROL LT
SOLENOID
AA
VIEW A-A
B1A1A2B2
8 7
3
VIEW ALL CALLOUTS

16. FAN AND BRAKE CONTROL
DD
38
45
VIEW ALL CALLOUTS

17. IMPLEMENT AND STEERING CIRCUIT
FW
D
S0S
1
AA
CC
SOS
2
BB
33
23
19
19 15
15
35
35
VIEW ALL CALLOUTSVIEW ALL CALLOUTS

18. SERVICE BRAKES
LH VIEW
FF (RH) (LH)EE
VIEW ALL CALLOUTS