432E, 434E, 442E, and 444E
Hydraulic SystemBackhoe Loader
HXB1-UPSXB1-UPPCR1-UPRXS1-UP
© 2008 Caterpillar, All Rights Reserved Printed in U.S.A.
KENR8042November 2008
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)
PRESSURECOMPENSATION
PUMP(VARIABLE & PRESSURE
COMPENSATED)
MEASUREMENT
PRESSURE TEMPERATURE FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
FIXEDDISPLACEMENT
VARIABLE DISPLACEMENTNON-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
BASICSYMBOL
SPRINGLOADED
CHECK VALVES
2 POSITIONINFINITE
POSITIONING
FLOW IN ONEDIRECTION
FLOW INEITHER
DIRECTION
3 POSITION
CROSSFLOW
PARALLELFLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
A B
P T
A B
P TSHIFTED POSITION INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOTCONTROLLED
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 TRIANGLESHYDRAULIC PNEUMATIC
INTERNALSUPPLY PRESSURE
COMPLETE
FIXEDDISPLACEMENT
VARIABLE DISPLACEMENTNON-COMPENSATED
HYDRAULIC SYMBOLS (ELECTRICAL)
ELECTRICAL SYMBOLS TABLE
325-AG135 PK-14
HARNESS IDENTIFICATION CODE THIS EXAMPLEINDICATES WIRE 135 IN HARNESS “AG”
325-PK-14
WIRE GAUGE
WIRE COLOR
CIRCUIT NUMBERIDENTIFICATION
WIRE NUMBER IDENTIFICATION CODES
CURRENT STANDARD
PREVIOUS STANDARD
ELECTRICAL SCHEMATIC EXAMPLE HYDRAULIC SCHEMATIC EXAMPLE
325-PK
WIRE COLORCIRCUIT NUMBER
IDENTIFICATION
B
WIRE
WIRE
(EXAMPLE VALVE)
CURRENT STANDARD
TRANSDUCER(FLUID)
MELECTRIC MOTORTRANSDUCER
(GAS / AIR)
G
GENERATOR
PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH(ADJUSTABLE)
TEMPERATURESWITCH
PRESSURESWITCH
TEMPERATURESWITCH
LEVELSWITCH
FLOWSWITCH
ELECTRICAL SYMBOLS (ELECTRICAL)
A
CIRCUIT NUMBERIDENTIFICATION
WIRECOLOR
WIRE GAUGE
T
KE
NR
8042
30
Pa
ge
, (D
ime
ns
ion
s:
39
in
ch
es
x 2
8 i
nc
he
s)
COMPONENT LOCATIONS
30 3119
14 15
14
2
2
15
3130
19
9
9
67
7
6
13
13
13
34
34
34
8
8
8
10
3
3
10
4
4
1211
11
12
33
33
32
323637
363735
23
23
352518
Tap DescriptionT1 Pump DischargeT2 Load Sense
SOS Oil Sampling
TAP LOCATIONS
BACKHOE VALVE
SOSImplement and Steering Pump
HYDRAULIC OIL FILTER
SOS Filter Bypass Switch
LOADER VALVE
E
DC
B
A
RIDE CONTROL
B
A
C
D
IMPLEMENT / STEERING PUMP
Implement and Steering Pump
F
View of mechanically controlled loader valve with floor plate removed.
Loader Valve
B C D
THREE BANK VALVE (PILOT OPERATED)
G
H J K L
M
P
R
N
E
G
A
B
E
F
D C
D
E
C
AB
T2
T2
T1
T2
T1
C
This illustration shows a sectional view of the boosted brake valve group. When the brake pedal is depressed, the boost brake valve moves to the left and inlet oil from the pilot manifold is directed to the master cylinder.
BOOSTED BRAKES
Drain
SEVEN BANK VALVE
For other bank valve configurations see RENR6487 (Specifications Manual).
For other bank valve configurations see RENR6487 (Specifications Manual).
SIDESHIFT
T3
Pilot Manifold
View of pilot controlled backhoe valve with floor plate removed.
The hydraulic oil filter is located below the machine at the left frame rail. The hydraulic oil filter bypass switch is mounted to the oil filter base.
(A) Outlet manifold (H) Solenoid for the A circuit (B)Auxiliary control valve (J) Makeup and relief valve (C) Tilt control valve (K) B pilot line port (D) Lift control valve (L) A pilot line port (E) Inlet manifold (M) Priority Valve (F) Load sensing relief valve (N) Dead engine lower valve (G) Solenoid for the B circuit (P) A ports
(R) B ports
SOS
ECM
Loader Valve
A
A
B
CD
To Wheel Brake
Boost Brake Valve
From PilotAccumulatorTo Tank
Master Cylinder
SlaveCylinder
A B
T3 Pilot Pressure
9
9
1
25
181
29
29
21
21
26
26
28
28
38
38
24
245 22
5 22
Hydraulic Oil Filter
Temp Sensor
Filter BypassSwitch
Temp Sensor
H
LINE MAKE-UP/RELIEF VALVE
STAB
BOOM
SWING
STAB
BUCKETSTICK
E-STICK
TANK (PLUGGED)GAUGE(PLUGGED)
SIDESHIFT CLAMP SOLENOID VALVE
M14x2
SIDESHIFT CLAMP
M14x2
PUMP (PLUGGED)
TANK (LS DRAIN)
LOAD SENSERELIEF VALVE
LOAD SENSE
(A) Ride Control Relay(B) Ride Control Solenoid(C) Ride Control Accumulator(D) Ride Control Pressure Switch
Description PartNumber
MachineLocation
SchematicLocation
5-C10240-622rotalumuccA2-B27487-403liO-relooC
Cylinder - Boom (432E/434E) 268-9049 (S) 3 F-5Cylinder - Boom (432E/434E) 210-7076 3 F-5Cylinder - Boom (442E/444E) 268-9051 (S) 3 F-5Cylinder - Boom (442E/444E) 246-9884 3 F-5Cylinder - Bucket (432E/434E) 210-7085 (S) 4 F-4Cylinder - Bucket (432E/434E) 210-7086 4 F-4Cylinder - Bucket (442E/444E) 210-7095 (S) 4 F-4Cylinder - Bucket (442E/444E) 210-7096 4 F-4
8-A55803-091relpuoC-rednilyCCylinder - Lift (PL/IT) 214-9373 6 B-8Cylinder - Lift LH (EST 434E) 249-6710 6 B-8Cylinder - Lift RH (EST 434E) 249-6711 7 C-8Cylinder - Lift LH (EST 444E) 249-6712 6 B-8Cylinder - Lift RH (EST 444E) 249-6713 7 C-8Cylinder - Stabilizer 173-4565 8 F-3/F-6Cylinder - Steer (Front) N/A 9 B-6Cylinder - Steer (Rear) N/A 9 B-5Cylinder - Stick (432E/434E) 210-7083 (S) 10 F-4Cylinder - Stick (432E/434E) 210-7084 10 F-4Cylinder - Stick (442E/444E) 210-7093 (S) 10 F-4Cylinder - Stick (442E/444E) 210-7094 10 F-4Cylinder - Swing (LH) 278-1971 11 F-5Cylinder - Swing (RH) 278-1973 12 F-5Cylinder - Tilt (PL/IT) 192-3884 13 B-8Cylinder - Tilt (EST 434E) 210-7101 13 B-8Cylinder - Tilt (EST 444E) 214-9372 13 B-8
2-B417526-523retliF6-A510426-012UMH
Manifold - Inlet (SS 7 bank) 308-2147 16 E-7Manifold - Outlet (SS 7Bank) 308-2154 17 E-2
5-C813944-003VRP-dlofinaM3-B910736-982pGpmuP
Valve - All Wheel Steer (434/444) 256-3089 20 A-4 to A-5Valve - Backhoe (SS) 7 Bank 293-8701 21 E-2 to E-7Valve - Control (Boom SS 7Bank) 308-2149 21 E-5Valve - Control (Bucket SS 7Bank) 308-2151 21 E-4Valve - Control (E-Stick 7Bank) 308-2153 21 E-3Valve - Control (Stick SS 7Bank) 308-2152 21 E-4Valve - Control (Stabilizer 7Bank) 308-2148 21 E-3 / E-6Valve - Control (Swing SS 7Bank) 308-2150 21 E-5
8-A225162-132relpuoC-evlaVValve - Loader (PL/IT) 3 Bank 293-8703 23 A-7 to C-7Valve - Control (Lift PL/IT 3Bank) 308-2157 23 B-7Valve - Control (Tilt PL/IT 3Bank) 308-2163 23 B-7Valve - Control (Aux PL/IT 3Bank) 308-2159 23 A-7Valve - Loader Inlet (PL/IT) 3Bank 308-2162 23 C-7Valve - Loader (EST) 293-8702 24 A-7 to C-7Valve - Control (Tilt EST 3Bank) 308-2158 24 B-7Valve - Loader Inlet (EST 3Bank) 308-2156 24 C-7Valve - Pattern Switching 300-4491 25 D-4Valve - Pilot (Switch) 297-4394 26 C-5Valve - Pilot (Switch + Detent) 297-4395 26 C-5Valve - Stabilizer PO Check 308-3437 27 F-3 / F-6Valve Gp - Pilot (Backhoe) 267-2758 28 C-3 / C-4Valve Gp - Pilot (Loader) 267-2760 29 C-6
2-A036825-642ciluardyH-knaT2-A137778-542pGknaT
Accumulator - Ride Control 162-3960 32 D-8Cylinder - E-Stick 210-7097 (S) 33 F-3
3-F338907-012kcitS-E-rednilyC8-A43A/NtekcuBPM-rednilyC
Sensor - Temperature N/A 35 B-2Switch - Differential Pressure 134-0404 35 B-2Switch - Ride Control Pressure 131-9203 36 C-8Valve - All Wheel Steer (432/442) 256-3089 20 A-4 to A-5Valve - Ride Control 245-8780 37 C-8Valve Gp - Cushion Relief 320-7812 38 F-5
Component Locations
Attachments
(A) Flow Compensator Adjustment Screw(B) Torque Control Spool Adjustment Screw(C) Inlet Port(D) Case Drain Port(E) Torque control Solenoid(F) Torque Limiter(H) Pump Control Valve(T1) Discharge pressure tap(T2) Load Sensing Pressure Tap
(A) Master Cylinder(B) Brake Pedal
(A) Hydraulic Cylinder(B) Wear Pad
(C) Wear Plate(D) Stabilizers
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling, Sensor - by letter)YY
HYDRAULIC CIRCUIT COLOR DESCRIPTIONSPILOT OIL CIRCUITIMPLEMENT AND STEERING PUMP CIRCUITLIFT CYLINDER CIRCUITBUCKET CYLINDER CIRCUITLOAD SENSE CIRCUITSTEERING CYLINDER CIRCUITSTICK CYLINDER CIRCUITSUPPLY LINEBOOM CYLINDER CIRCUITTILT CYLINDER CIRCUITAUXILIARY CIRCUIT (LOADER VALVE)DRAIN / RETURN LINESTABILIZER CYLINDER CIRCUITSWING CYLINDER CIRCUITE-STICK CYLINDER CIRCUITSIDESHIFT LOCK CYLINDER CIRCUITBOOSTED BRAKE OIL CIRCUIT
KE
NR
8042
30
Pa
ge
, (D
ime
ns
ion
s:
39
in
ch
es
x 2
8 i
nc
he
s)
THIS SCHEMATIC IS FOR THE 432E, 434E, 442E, AND 444E BACKHOE LOADERMEDIA NUMBER: KENR8042PART NUMBER: 322-3114, CHANGE: 00, VERSION: SComponents are shown installed on a fully operable machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications.
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
LOADER VALVE
PT DLS
LS
D
LIFT
a1
B1
A1
a2
B2
A2
TILT
AUX
T2
P
P2
LS
B1 A1 B2 A2 B3 A3 B4 A4 B5 A5 B6 A6 B7 A7
T b1 a1 b2 b3 a3 b4 a4 b5 a5 b6 a6 b1 a1
STAB BOOM BUCKETSWING STICK E-STICK STAB
a2
T1
T3
C
b1
b2
a3
b3
BACKHOE VALVE
M
A3
B3
SWINGCYLINDER
278-1971(LH)278-1973(RH)
CUSHION RELIEFVALVE GROUP(ATCH)320-7812
E-STICK CYLINDER(ATCH)210-7097(S)/210-7098
BOOMCYLINDER
210-7076 (432E/434E)246-9884 (442E/444E)
RIDE CONTROLACCUMULATOR(ATCH)162-3960
RIDE CONTROLPRESSURESWITCH (ATCH)131-9203
RIDE CONTROLVALVE (ATCH)245-8780
INLET SECTION(434E/444E)308-2156
LIFT CYL(PL/IT) 214-9373(EST) 249-6710(LH) 249-6711(RH)
TILT CYL(PL/IT)192-3884
MP BUCKET CYL(ATCH)
COUPLERCYLINDER190-3085
COUPLERVALVE231-2615
HMU210-6240
FRONTSTEERCYLINDER
REARSTEERCYLINDER
ALL WHEELSTEERVALVE256-3089(434E/444E)(ATCH)-256-3089(432E/442E)
TEMPERATURESENSOR(ATCH)
DIFFERENTIALPRESSURESWITCH(ATCH)134-0404
OIL COOLER
FILTER325-6257
PUMP GP289-6370
HYDRAULICTANK
246-5286
TANKGROUP245-8777
INLETMANIFOLD308-2147
STABILIZERSECTION308-2148
STABILIZERCYLINDER173-4565
STABILIZERPO CHECKVALVE308-3437
BUCKET CYLINDER(210-7085(S)/210-7086)(432E/434E)(210-7095(S)/210-7096)(442E/444E)
STICK CYLINDER(210-7083(S)/210-7084)(432E/434E)(210-7093(S)/210-7094)(442E/444E)
STABILIZERPO CHECKVALVE308-3437
STABILIZERCYLINDER173-4565
BACKHOEVALVE (SS)293-8701
OUTLETMANIFOLD308-2154
STABILIZERSECTION308-2150
E-STICKSECTION308-2153
STICKSECTION308-2152
PATTERNSWITCHINGVALVE300-4491
BUCKETSECTION308-2151
SWINGSECTION308-2150
BOOMSECTION308-2149
LOADERVALVE (EST)293-8702
AUX SECTION308-2159
TILT SECTION308-2158
LIFT SECTION308-2157
P6 P5 P7 P8
P1 P2 P3 P4
RR LR
RHMU
b
aLF
T
P
T
PS
R L
LS
PT
B
S L1 L
X
R HAWS ELECTRICALPRESSURE SWITCH
RIGHT JOYSTICK
BOOM BUCKET
PT
1
23
4
LEFT JOYSTICK
STICK SWING
PT
1
2 3
4
STABILIZER LEVERS
LH RH
PT
1
2 3
4
LOADER JOYSTICK
LIFT TILT
1 2 3 4
PT
FLOATELECTRICAL
PRESSURESWITCH
IN
T
T1
T2 A1 A2 B2
P1 P2 P3
T3
B1
ACC
BOOSTED BRAKES (REF)
LEFT BRAKE PEDAL
RIGHT BRAKE PEDAL
TO REAR AXLE
LEFT WHEEL BRAKE
TO REAR AXLE
RIGHT WHEEL BRAKE
T2
T1
T3