420D, 432D and 442D
Hydraulic System
Backhoe Loader
432D:
WEP1-UP
TDR1-UP
442D:
TBD1-UP
SMJ1-UP
420D:
BKC1-UP
BMC1-UP
Volume 1 of 2: Single Tilt Loader With Center Pivot Backhoe
© 2010 Caterpillar, All Rights Reserved Printed in U.S.A.
RENR7783-02
August 2010
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)
PUMP
(2 - SECTION)
SPRING
(ADJUSTABLE)
VARIABILITY LINE RESTRICTION
(VARIABLE)
PRESSURE
COMPENSATION
PUMP
(VARIABLE & PRESSURE
COMPENSATED)
MEASUREMENT
PRESSURE TEMPERATURE FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVE ENVELOPES VALVE PORTS
FLUID CONDITIONERPUMP OR MOTOR
FLUID POWER SYMBOLS
UNIDIRECTIONAL
BIDIRECTIONAL
RELEASED PRESSURE
EXTERNAL RETURN INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
HYDRAULIC PUMPS
ACCUMULATORS
SPRING LOADED GAS CHARGED
SOLENOID
OR MANUAL
SOLENOID
& PILOT
SOLENOID &
PILOT OR MANUAL
SOLENOID SERVO THERMAL DETENT
HYDRAULIC & PNEUMATIC CYLINDERS
DOUBLE ACTINGSINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
2 POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW IN
EITHER
DIRECTION
3 POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
AB
PT
AB
PT
SHIFTED POSITION INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
MAIN AUX
LINE RESTRICTION
(VARIABLE & PRESSURE
COMPENSATED)
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FLUID STORAGE RESERVOIRS
CROSSING & JOINING LINES
VALVES
PILOT CONTROL SYMBOLS
COMBINATION CONTROLS
BASIC COMPONENT SYMBOLS
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
INTERNAL
SUPPLY PRESSURE
COMPLETE
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
HYDRAULIC SYMBOLS (ELECTRICAL)
ELECTRICAL SYMBOLS TABLE
325-AG135 PK-14
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
WIRE
WIRE
(EXAMPLE VALVE)
CURRENT STANDARD
TRANSDUCER
(FLUID)
M
ELECTRIC MOTORTRANSDUCER
(GAS / AIR)
G
GENERATOR
PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH
(ADJUSTABLE)
TEMPERATURE
SWITCH
PRESSURE
SWITCH
TEMPERATURE
SWITCH
LEVEL
SWITCH
FLOW
SWITCH
ELECTRICAL SYMBOLS (ELECTRICAL)
A
CIRCUIT NUMBER
IDENTIFICATION
WIRE
COLOR
WIRE GAUGE
T
RENR7783-02 VOL 1 of 2
30 Page, (Dimensions: 39 inches x 28 inches)
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator - Pilot Pressure 149-0686 1 G-6
Valve - Stabilizer 192-0827 39 G-1, G-5
Cartridge - P.O. Check 213-4072 2 C-3 , C-7
Valve - Steer Priority 188-7471 40 E-10
Connector - Orifice (Loader Valve) 220-8219 3 E-9
Valve - Stick 201-0669 41 C-3
Connector - Orifice ( Left Hand Joystick) 164-9639 4 B-7
Valve - Swing 201-5357 42 C-6
Connector - Orifice (Switching Valve) 220-8219 5 A-6
Valve - Tilt 201-5377 43 G-10
Cooler - Radiator 235-1974 6 B-15
Valve - Tilt Down Pressure Limiter 210-6171 44 G-10
Cover - End 191-4010 7 I-9
Valve Gp - 2 Bank Loader 200-7827 45 E-9
Cover - End (Backhoe Valve) 6E-4158 8 C-1
Valve Gp - Cushion Relief 206-3685 46 D-5
Cover Gp - Inlet 211-0180 9 C-9
Valve Gp - P.C.F.R. 212-0732 47 C-9
Cylinder - Boom 206-3630 10 D-8
Valve Gp - Pilot / Left Hand Joystick 185-5916 48 A-8
Cylinder - Bucket 191-7835 11 D-4
Valve Gp - Pilot / Right Hand Joystick 185-5915 49 A-3
Cylinder - Lift (ST) 230-0980 12 G-11
Valve Gp - Pilot Shut Off 233-7132 50 F-7
Cylinder - Stabilizer (Left) 228-3499 13 H-4
Valve Gp - P-Lever 2 Bank/Detents/SW 185-5900 51 G-7
Cylinder - Stabilizer (Right) 228-3500 14 H-2
Valve Gp - Pressure Reducing 239-2226 52 F-6
Cylinder - Steer 167-4325 15 E-13
Valve Gp - Stabilizer (2 Bank RE-Relief) 185-5898 53 G-1
Cylinder - Stick 235-9829 16 D-3
Cylinder - Swing 228-3506 17 D-6
Cylinder - E-Stick 191-7725 1A C-2
Cylinder - Tilt (ST) 200-7128 18 H-11
Cylinder - E-Stick Bucket 191-7839 2A D-4
Filter 210-6243 19 G-13
Cylinder - MP Bucket 185-1839 3A I-13
Hand Metering Unit (HMU) 238-8550 20 D-14
Valve - Auxiliary (Backhoe Valve) 190-3450 4A C-8
Manifold - Return 186-3629 21 F-7
Valve - Auxiliary (Loader Valve) 124-8818 5A H-10
Pump Gp 244-2228 22 B-13
Tank Gp - Hydraulic 240-9721 23 B-14
Valve - Backhoe (5 Bank) 201-0666 7A C-1
Valve - Backhoe (6 Bank) 201-0667 9A C-1
Valve - Backhoe 201-0665 25 C-1
Valve - E-Stick 201-0664 10A C-1
Valve - Boom 201-0668 26 C-7
Valve - Line Relief (Aux Loader Valve) 9T-0704 11A I-9
Valve - Bucket 201-5358 27 C-4
Valve - Line Relief (E-Stick) 132-5303 12A C-2
Valve - Check 214-3524 28 C-10
Valve - Pressure Controller (E-Stick) 211-3539 13A C-2
Valve - Lift 130-6520 29 F-10
Valve - Switching 164-2274 14A A-6
Valve - Line Relief (Boom) 187-0523 30 C-8
Valve Gp - 3 Bank Loader 200-7828 15A E-9
Valve - Line Relief (Boom) 6E-6285 31 C-8
Valve - Line Relief (Bucket) 187-0524 32 C-5
Accumulator - Ride Control 162-3960 1B D-12
Valve - Line Relief (Bucket) 187-0527 33 C-5
Switch - Pressure 131-9203 2B C-11
Valve - Line Relief (Stick) 187-0529 34 C-3
Valve Gp - Ride Control 243-2266 3B D-12
Valve - Line Relief (Stick) 187-0528 35 C-3
Valve - Line Relief (Swing) 137-9466 36 C-6
Valve - Line Relief (Tilt) 6E-6285 37 H-9
Valve - Line Relief (Tilt) 204-4313 38 H-9
Component Locations (Volume 1)
Attachments
Ride Control
44
15
3A
35A7
11A 15A
29
37 38 40
18
3B
21
1
51
14 39
52 53
13
8
30
24A5
7A
99A
10A 12A 13A
25 26 27 28
31
32
33
34
35
36
41
42
46
47
2A 11
1A
16
17
14A
449
10
20
23
6
12
2B1B
50
19 22
43
45
48
MACHINE COMPONENT LOCATIONS
Switch - Differential Pressure
134-0404
G-13
Tap Locations (Volume 1)
Pressure, Sampling, and Sensor
Tap
Number
Description
Schematic
Location
AA Pump Pressure Test Port A-12
BB Pump Signal Pressure Test Port B-12
CC Pilot Pressure Test Port G-6
Description
Media Number
420D Backhoe Loader (BKC)
SEBP3583
420D Backhoe Loader (BMC)
SEBP3584
432D Backhoe Loader (WEP & TDR)
SEBP3971
442D Backhoe Loader (TBD & SMJ)
SEBP3967
Specifications: (Hydraulic & Steering System)
RENR7778
Testing and Adjusting: (Hydraulic & Steering System)
RENR7779
Specifications: (Axles, Differentials & Brakes)
RENR7776
Testing and Adjusting: (Axles, Differentials & Brakes)
RENR7777
Schematic: (Electrical system)
RENR7781
Related Manuals
Parts Manual
Machine System
Electrical System
22. Hydraulic Pump
19. Filter
45. Loader Valve Group
BB. Signal Pressure Test Port
22. Hydraulic Pump
AA. Pump Pressure Test Port
AA
22
1. Pilot Accumulator
52. Pressure Reducing Valve (Stabilizer)
CC. Pilot Oil Pressure Test Port
HYDRAULIC PUMP
PRESSURE REDUCING VALVE
PILOT SHUT OFF VALVE
54
The Ride Control Valve (3B) is located on the inside of the
right frame rail below the cab.
1B. Accumulator
2B. Pressure Switch
3B. Ride Control Valve
RIDE CONTROL
54
1B
2B
Ride Control
Pressure Switch
F738-WH
200-BK
The Pilot Shutoff Valve (50) is mounted to the front of the
rear axle. The optional Pattern Changeover Valve (47) for
the Backhoe Valve Group is mounted on the right side of the
rear frame. The valve allows the operator to change from the
excavator pattern to the backhoe pattern. Also shown is the
Pilot Return Manifold (21).
BACKHOE VALVE GROUP
The pilot operated Backhoe Valve Group (25) is located at
the rear of the machine. Outlet ports to the cylinders face
the rear of the machine on all models.
25. Backhoe Valve Group
26. Boom Valve
42. Swing Valve
27. Bucket Valve
41. Stick Valve
10A. E-Stick Valve
LOADER VALVE GROUP
The Loader Valve Group (45) consists of an inlet manifold
with a Steering Priority Valve (40), a loader Lift Control
Valve (29), a Tilt Control Valve (43), and an optional
Auxiliary Valve (5A).
HYDRAULIC TANK
The Hydraulic Tank (23) is located between the engine and
the cab. The sight gauge is located on the side of the tank.
CC
52
1
3B
1B
Ride Control
Solenoid
976-OR
200-BK
50
21
45
19
22
BB
25
26
42
41
10A
27
5A
43
29
40
23
Sight Gauge
Drain Tube
47
RENR7783-02 VOL 1 of 2
30 Page, (Dimensions: 39 inches x 28 inches)
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.
420D, 432D AND 442D BACKHOE LOADER
VOLUME 1 of 2: SINGLE TILT LOADER W/ CENTER PIVOT BACKHOE
PART NUMBER: 201-6839, CHANGE: 06, VERSION: (-)
RENR7783-02
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
Main Pump Output.
Load Sense Circuit.
Supply Line.
Drain / Return Line.
Hand Metering Unit Control Circuit.
Lift Cylinder Control Circuit.
Auxiliary Control Circuit.
Tilt Cylinder Control Circuit.
Pilot Shutoff Control Circuit.
Bucket Cylinder Control Circuit.
Boom Cylinder Control Circuit.
Swing Cylinder Control Circuit.
Bucket / E-Stick Control Circuit.
Stick Cylinder Control Circuit.
Stabilizer Cylinder Control Circuit.
Stabilizer Cylinder Control Circuit.
E-Stick Cylinder Control Circuit.
PRESSURE SWITCH
134-0404
CYLINDER
MP BUCKET
185-1839
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
SIGNAL
PRESSURE
ACC
H
R
T
PUMP
PRESSURE
HMU
PUMP
VALVE
LINE RELIEF
6E-6285
VALVE
TILT
201-5377
VALVE
LIFT
130-6520
VALVE GP
2 BANK LOADER
200-7827
PUMP GP
244-2228
TANK GP
HYDRAULIC
240-9721
COOLER
RADIATOR
235-1974
HMU
238-8550
CYLINDER
LIFT
230-0980
CYLINDER
TILT
200-7128
CYLINDER
STEER
167-4235
VALVE GP (ATTCH)
3 BANK LOADER
200-7828
VALVE
STEER PRIORITY
188-7471
VALVE
AUXILIARY
124-8818
VALVE
LINE RELIEF
9T-0704
LIFT
TILT
AUX
VALVE GP
RIDE CONTROL
243-2266
ACCUMULATOR
162-3960
SWITCH
PRESSURE
RIDE CONTROL
131-9203
END COVER
191-4010
VALVE
LINE RELIEF
204-4313
VALVE
TILT DOWN
PRESS LIMITER
210-6171
CONNECTOR
ORIFICE
220-8219
P1
PILOT
PRESSURE
USED WITH
AWS
USED WITH
NON-AWS
CYLINDER (ATTCH)
E-STICK BUCKET
191-7839
AUX BOOM
SWING
BUCKET
STICK
E-STICK
CYLINDER
BOOM
206-3630
CYLINDER
SWING
228-3506
CYLINDER
BUCKET
191-7835
CYLINDER
STICK
235-9829
CYLINDER
E-STICK
191-7725
VALVE
E-STICK
201-0664
VALVE
BUCKET
201-5358
VALVE
STICK
201-0669
VALVE
SWING
201-5357
VALVE
BOOM
201-0668
VALVE
AUXILIARY
190-3450
BOOM UP
RIGHT
LEFT
BOOM DOWN
DUMP
STICK OUT
STICK IN
CURL
VALVE GP - PILOT
LEFT HAND JOYSTICK
185-5916
VALVE GP - PILOT
RIGHT HAND JOYSTICK
185-5915
VALVE GP
STABILIZER
2 BANK
185-5898
UP
DOWN UP
DOWN
VALVE GP
PILOT SHUT OFF
233-7132
VALVE
SWITCHING
164-2274
STABILIZER (LEFT)
STABILIZER (RIGHT)
VALVE GP - PILOT
2 BANK STABILIZER
185-5900
CYLINDER
STABILIZER
228-3499
CYLINDER
STABILIZER
228-3500
VALVE
BACKHOE
6 BANK
201-0667
VALVE
BACKHOE
5 BANK
201-0666
VALVE
BACKHOE
201-0665
COVER GP
INLET
211-0180
T1
T3
T4
RETURN
MANIFOLD
186-3629
S2
S3
S1
P
T
S
VALVE GP
PRESSURE
REDUCING
239-2226
ACCUMULATOR
149-0686
USED WITH PL LOADER
VALVE GP
CUSHION RELIEF
206-3685
END COVER
6E-4158
VALVE
P.C.F.R.
212-0732
VALVE
PRESSURE
CONTROLLER
211-3539
VALVE
LINE RELIEF
132-5303
VALVE
CHECK
214-3524
CARTRIDGE
P.O. CHECK
213-4072
CARTRIDGE
P.O. CHECK
213-4072
CONNECTOR
ORIFICE
164-9639
CONNECTOR
ORIFICE
220-8219
VALVE
LINE RELIEF
187-0528
VALVE
LINE RELIEF
187-0524
VALVE
LINE RELIEF
187-0527
VALVE
LINE RELIEF
187-0529
VALVE
LINE RELIEF
137-9466
VALVE
LINE RELIEF
137-9466
VALVE
LINE RELIEF
187-0523
VALVE
LINE RELIEF
6E-6285
AA
BB
CC
PS
A
B
C
D
E
F
G
H
I
A
B
C
D
E
F
G
H
I
151413121110987654321
151413121110987654321
FILTER GP
210-6243
VALVE
STABILIZER
192-0827
420D, 432D and 442D
Hydraulic System
Backhoe Loader
432D:
WEP1-UP
TDR1-UP
442D:
TBD1-UP
SMJ1-UP
420D:
BKC920-UP
BMC1060-UP
Volume 2 of 2: Parallel Lift Loader With Center Pivot Or Side Shift Backhoe
© 2010 Caterpillar, All Rights Reserved Printed in U.S.A.
RENR7783-02
August 2010
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)
PUMP
(2 - SECTION)
SPRING
(ADJUSTABLE)
VARIABILITY LINE RESTRICTION
(VARIABLE)
PRESSURE
COMPENSATION
PUMP
(VARIABLE & PRESSURE
COMPENSATED)
MEASUREMENT
PRESSURE TEMPERATURE FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVE ENVELOPES VALVE PORTS
FLUID CONDITIONERPUMP OR MOTOR
FLUID POWER SYMBOLS
UNIDIRECTIONAL
BIDIRECTIONAL
RELEASED PRESSURE
EXTERNAL RETURN INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
HYDRAULIC PUMPS
ACCUMULATORS
SPRING LOADED GAS CHARGED
SOLENOID
OR MANUAL
SOLENOID
& PILOT
SOLENOID &
PILOT OR MANUAL
SOLENOID SERVO THERMAL DETENT
HYDRAULIC & PNEUMATIC CYLINDERS
DOUBLE ACTINGSINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
2 POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW IN
EITHER
DIRECTION
3 POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
AB
PT
AB
PT
SHIFTED POSITION INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
MAIN AUX
LINE RESTRICTION
(VARIABLE & PRESSURE
COMPENSATED)
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FLUID STORAGE RESERVOIRS
CROSSING & JOINING LINES
VALVES
PILOT CONTROL SYMBOLS
COMBINATION CONTROLS
BASIC COMPONENT SYMBOLS
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
INTERNAL
SUPPLY PRESSURE
COMPLETE
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
HYDRAULIC SYMBOLS (ELECTRICAL)
ELECTRICAL SYMBOLS TABLE
325-AG135 PK-14
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
WIRE
WIRE
(EXAMPLE VALVE)
CURRENT STANDARD
TRANSDUCER
(FLUID)
M
ELECTRIC MOTORTRANSDUCER
(GAS / AIR)
G
GENERATOR
PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH
(ADJUSTABLE)
TEMPERATURE
SWITCH
PRESSURE
SWITCH
TEMPERATURE
SWITCH
LEVEL
SWITCH
FLOW
SWITCH
ELECTRICAL SYMBOLS (ELECTRICAL)
A
CIRCUIT NUMBER
IDENTIFICATION
WIRE
COLOR
WIRE GAUGE
T
RENR7783-02 VOL 2 of 2
30 Page, (Dimensions: 39 inches x 28 inches)
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator - Pilot Pressure 149-0686 1 H-6
Valve - Swing 191-4483 41 D-6
Connector - Orifice (Loader Valve) 220-8219 2 E-11
Valve - Tilt 194-6758 42 G-11
Connector - Orifice ( Loader Joystick) 164-9639 3 C-5, C-4, B-10, B-9
Valve Gp - 2 Bank Loader 179-8289 43 E-10
Cover Gp - Pressure Reducing Valve 239-2226 4 G-5
Valve Gp - P.C.F.R. 212-0732 44 D-9
Cooler - Radiator 235-1974 5 C-15
Valve Gp - Pilot / Left Hand Joystick 185-5916 45 B-5
Cover - End (2 Stack Only) 105-4910 6 I-10
Valve Gp - Pilot / Loader Joystick 187-0521 46 A-10
Cover - End (Backhoe Valve) 193-9189 7 D-1
Valve Gp - Pilot / Right Hand Joystick 185-5915 47 B-2
Cover Gp - Inlet 211-0180 8 D-8
Valve Gp - Pilot Shut Off 233-7132 48 G-6
Cylinder - Boom 206-3630 9 E-7
Valve Gp - Side Shift Clamp 3E-8622 49 D-1
Cylinder - Bucket 191-7835 10 E-4
Valve Gp - Stabilizer (2 Bank RE-Relief) 185-5898 50 I-1
Cylinder - Lift (IT) (420D)
Cylinder - Lift (IT) (432D & 442D)
228-3505
192-3791
11 F-12
Cylinder - Stabilizer 173-4565 12 I-2, I-4
Cover Gp - Used W/ Aux Loader Valve
194-6763 1A I-10
Cylinder - Steer 167-4235 13 H-12
Cylinder - AWD Steer (Front) 214-5097 2A H-12
Cylinder - Stick 235-9831 14 E-3
Cylinder - Coupler 178-3713 3A H-12
Cylinder - Swing 228-3507 15 E-6
Cylinder - E-Stick 191-7725 4A E-2
Cylinder - Swing 228-3506 16 E-6
Cylinder - E-Stick Bucket 191-7839 5A E-4
Cylinder - Tilt (IT) 192-3884 17 G-12
Cylinder - MP Bucket 185-1839 6A H-12
Filter 210-6243 18 D-15
Motor - Broom - - - - 7A I-12
Hand Metering Unit (HMU) 238-8550 19 F-14
Valve - Auxiliary (Loader Valve) 194-6760 8A H-10
Manifold - Return 186-3629 20 H-7
Valve - Backhoe (5 Bank) 230-1460 10A D-1
Valve - Backhoe (6 Bank) 230-1461 11A D-1
Tank Gp - Hydraulic 240-9721 22 B-14
Valve - Coupler 138-1979 12A H-11
Switch - Differential Pressure 134-0404 23 D-15
Valve - E-Stick 190-3450 13A D-2, D-8
Valve - Backhoe (4 Bank) 230-1459 24 D-1
Valve - Line Relief (Aux Loader Valve) 9T-0704 14A H-10
Valve - Boom 191-4480 25 D-7
Valve - Switching 164-2274 15A B-3
Valve - Bucket 191-4484 26 D-4
Valve Gp - 3 Bank Loader 179-8290 16A E-10
Valve - Check 214-3524 27 E-9
Valve Gp - Cushion Relief 206-3685 17A E-5
Valve - Lift 194-6757 28 F-11
Valve Gp - Diverter Solenoid 201-0947 18A H-11
Valve - Line Relief (Boom) 187-0523 29 D-7
Valve - Line Relief (Boom) 6E-6285 30 D-7
Cylinder - Rear Steer 110-0873 1B I-14
Valve - Line Relief (Bucket) 187-0524 31 D-4
Switch - Pressure 128-5091 2B E-14
Valve - Line Relief (Bucket) 187-0527 32 D-4
Valve Gp - All Wheel Steer 121-4449 3B G-14
Valve - Line Relief (Stick) 187-0529 33 D-3
Valve - Line Relief (Stick) 187-0528 34 D-3
Accumulator - Ride Control 162-3960 1C F-13
Valve - Line Relief (Swing) 137-9466 35 D-6
Switch - Pressure 131-9203 2C E-12
Valve - Line Relief (Tilt) 187-0532 36 G-11
Valve Gp - Ride Control 252-0634 3C F-13
Valve - Line Relief (Tilt) 197-3124 37 G-10
Valve - Stabilizer 222-0364 38 H-2, H-4
Valve - Steer Priority 200-6378 39 E-11
Valve - Stick 191-4485 40 D-3
Component Locations (Volume 2)
Attachments
Ride Control
Pump Gp (420D)
Pump Gp (432D & 442D)
21 B-13
244-2228
235-4109
All Wheel Steer
Tap Locations (Volume 2)
Pressure, Sampling, and Sensor
Tap
Number
Description
Schematic
Location
AA Pump Pressure Test Port A-12
BB Pump Signal Pressure Test Port B-12
CC Pilot Pressure Test Port H-5
Description Media Number
420D Backhoe Loader (BKC) SEBP3583
420D Backhoe Loader (BMC) SEBP3584
432D Backhoe Loader (WEP & TDR) SEBP3971
442D Backhoe Loader (TBD & SMJ) SEBP3967
Specifications: (Hydraulic & Steering System) RENR7778
Testing and Adjusting: (Hydraulic & Steering System) RENR7779
Specifications: (Axles, Differentials & Brakes) RENR7776
Testing and Adjusting: (Axles, Differentials & Brakes) RENR7777
Schematic: (Electrical system) RENR7781
Related Manuals
Parts Manual
Machine System
Electrical System
1B
2A
3B
13
3A
7A
12A
18A
6A
17
2
6
8A
14A
16A
28
36
37
42
43
11
1C 2C
3C
22
18
1A
346
4
21
12
5
11A
13A
50
1
38
19
2B
48
20
23
9
15
16
5A
10
14
47
45
15A
10A
8
7
27
26
25
24
17A
33
32
31
30
29
44
41
40
35
34
72
73
74
75
49
77
4A
MACHINE COMPONENT LOCATIONS
4B
5B
Valve - Shuttle 8J-6875
Orifice - Check 255-7117
23
4B
5B
21. Hydraulic Pump
18. Filter
43. Loader Valve Group
BB. Signal Pressure Test Port
21. Hydraulic Pump
AA. Pump Pressure Test Port
AA
21
HYDRAULIC PUMP
The Ride Control Valve (3C) is located on the inside of the
right frame rail below the cab.
1C. Accumulator
2C. Pressure Switch
3C. Ride Control Valve
RIDE CONTROL
1C
2C
Ride Control
Pressure Switch
F738-WH
200-BK
PILOT SHUT OFF VALVE
The Pilot Shutoff Valve (48) is mounted to the front of the
rear axle. The optional Pattern Changeover Valve (44) for
the Backhoe Valve Group is mounted on the right side of the
rear frame. The valve allows the operator to change from the
excavator pattern to the backhoe pattern. Also shown is the
Pilot Return Manifold (20).
BACKHOE VALVE GROUP
The pilot operated Backhoe Valve Group (24) is located at
the rear of the machine. Outlet ports to the cylinders face
the rear of the machine on all models.
24. Backhoe Valve Group
25. Boom Valve
41. Swing Valve
26. Bucket Valve
40. Stick Valve
13A. E-Stick Valve
LOADER VALVE GROUP
The Loader Valve Group (43) consists of an inlet manifold
with a Steering Priority Valve (39), a loader Lift Control
Valve (28), a Tilt Control Valve (42), and an optional
Auxiliary Valve (8A).
HYDRAULIC TANK
The Hydraulic Tank (22) is located between the engine and
the cab. The sight gauge is located on the side of the tank.
1. Pilot Accumulator
4. Pressure Reducing Valve (Stabilizer)
CC. Pilot Oil Pressure Test Port
PRESSURE REDUCING VALVE
FRONT VIEW
LEFT SIDE VIEW
3A
12A
12A
3A. Coupler Cylinder
12A. Coupler Valve
Coupler Solenoid
163-WH
779-WH
COUPLER CYLINDER / VALVE
AWS
Pressure
Switch
G787-BR
E764-OR
AWS PRESSURE SWITCH
2B. All Wheel Steer Pressure Switch
G-14
H-14
43
18
21
BB
3C
1C
Ride Control
Solenoid
976-OR
200-BK
48
20
44
24
25
41
40
13A
26
8A
42
28
39
22
Sight Gauge
Drain Tube
CC
4
1
2B
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
Main Pump Output.
Load Sense Circuit.
Supply Line.
Drain / Return Line.
Hand Metering Unit Control Circuit.
Lift Cylinder Control Circuit.
Auxiliary Control Circuit.
Tilt Cylinder Control Circuit.
Pilot Shutoff Control Circuit.
Bucket Cylinder Control Circuit.
Boom Cylinder Control Circuit.
Swing Cylinder Control Circuit.
Bucket / E-Stick Control Circuit.
Stick Cylinder Control Circuit.
Stabilizer Cylinder Control Circuit.
Stabilizer Cylinder Control Circuit.
E-Stick Cylinder Control Circuit.
AWS Cylinder Control Circuit.
RENR7783-02 VOL 2 of 2
30 Page, (Dimensions: 39 inches x 28 inches)
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.
420D, 432D AND 442D BACKHOE LOADER
VOLUME 2 of 2: PARALLEL LIFT LOADER WITH CENTER PIVOT OR SIDE SHIFT LOADER
PART NUMBER: 201-6839, CHANGE: 06, VERSION: (-)
RENR7783-02
A
B
C
D
E
F
G
H
I
A
B
C
D
E
F
G
H
I
151413121110987654321
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
VALVE
LINE RELIEF
187-0524
VALVE
LINE RELIEF
187-0527
AA
BB
CC
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
PRESSURE SWITCH
134-0404
NOT USED
WITH AWS
SIGNAL
PRESSURE
PUMP
PRESSURE
HMU
(NOT USED ON
420 NACD)
PUMP
LIFT
TILT
AUX
COOLER
RADIATOR
235-1974
TANK GP
HYDRAULIC
240-9721
PUMP GP
244-2228 (420)
235-4109 (432/442)
HMU
238-8550
SWITCH
PRESSURE (AWS)
128-5091 (442)
VALVE
STEER PRIORITY
200-6378
VALVE
LIFT
194-6757
VALVE
TILT
194-6758
CYLINDER
LIFT (IT)
228-3505 (420)
192-3791 (432/442)
VALVE
LINE RELIEF
9T-0704
CYLINDER
MP BUCKET
185-1839
CYLINDER
STEER
167-4235
VALVE GP
2 BANK LOADER
179-8289
VALVE GP
3 BANK LOADER
179-8290
CYLINDER
TILT
192-3884
RACK BACK
RAISE
LOWER /
FLOAT
DUMP/
REGEN
WIRED TO
CONTROLLER
VALVE GP - PILOT
LOADER JOYSTICK
187-0521
CONNECTOR
ORIFICE
164-9639
CONNECTOR
ORIFICE
164-9639
COVER GP
105-4910
COVER GP
AUXILIARY
194-6763
VALVE GP
DIVERTER
201-0947
CYLINDER
COUPLER
178-3713
MOTOR
BRUSH
CONNECTOR
ORIFICE
220-8219 (420)
VALVE
COUPLER
138-1979
RS
LS
PILOT
PRESSURE
USED WITH
NON-AWS
USED WITH
AWS
CYLINDER
BUCKET
E-STICK
191-7839
CYLINDER
BOOM
206-3630
CYLINDER
SWING
228-3506
CYLINDER
BUCKET
191-7835
CYLINDER
STICK
235-9831
CYLINDER
E-STICK
191-7725
VALVE
E-STICK
190-3450
VALVE
LINE RELIEF
187-0528
VALVE
LINE RELIEF
137-9466
VALVE
LINE RELIEF
6E-6285
VALVE
BUCKET
191-4484
VALVE
LINE RELIEF
187-0529
VALVE
STICK
191-4485
VALVE
SWING
191-4483
VALVE
BOOM
191-4480
VALVE
LINE RELIEF
187-0523
VALVE
E-STICK
190-3450
BOOM UP
RIGHT
LEFT
BOOM DOWN
DUMP
STICK OUT
STICK IN
CURL
VALVE GP - PILOT
LEFT HAND JOYSTICK
185-5916
VALVE GP - PILOT
RIGHT HAND JOYSTICK
185-5915
VALVE GP
PILOT SHUT OFF
233-7132
VALVE
SWITCHING
164-2274
STABILIZER
STABILIZER
CYLINDER
STABILIZER
173-4565
CYLINDER
STABILIZER
173-4565
AUX
BOOM
SWING
BUCKET
STICK
E-STICK
COVER GP
193-9189
VALVE GP
SIDE SHIFT
CLAMP
3E-8622
CYLINDER
SWING
228-3507
COVER GP
INLET
211-0180
T1
T3
T4
P1
S2
P
T
RETURN MANIFOLD
186-3629
S3
S
S1
COVER GP
PRESS REDUCING
239-2226
ACCUMULATOR
149-0686
T5
VALVE GP
CUSHION RELIEF
206-3685
VALVE GP
P.C.F.R.
212-0732
VALVE
CHECK
214-3524
VALVE
LINE RELIEF
187-0532
CONNECTOR
ORIFICE
164-9639
CONNECTOR
ORIFICE
164-9639
VALVE
STABILIZER
222-0364
VALVE GP
STABILIZER
2 BANK
185-5898
VALVE
BACKHOE
6 BANK
230-1461
VALVE
BACKHOE
5 BANK
230-1460
VALVE
BACKHOE
4 BANK
230-1459
VALVE
AUXILIARY
194-6760
FRONT OF MACHINE
FRONT AXLE
(CYLINDER IS IN
FRONT OF AXLE)
CYLINDER
STEER (AWD)
214-5097
CYLINDER
REAR STEER (442)
110-0873
REAR AXLE
(CYLINDER IS IN
FRONT OF AXLE)
RHMU
LF
RR
LR
USED WITH
AWS
AWS VALVE
VALVE GP
(AWS)
252-0634 (442)
VALVE
SHUTTLE
8J-6875
ORIFICE
CHECK
255-7117
ORIFICE
CHECK
255-7117
LS1
VALVE
LINE RELIEF
197-3124
FILTER GP
210-6243
ACC
H
R
T
VALVE GP
RIDE CONTROL
243-2266
ACCUMULATOR
162-3960
SWITCH
PRESSURE
RIDE CONTROL
131-9203
PS
LS
RS
