FLUID POWER SYMBOLS
RENR6484-03 December 2008
BASIC COMPONENT SYMBOLS
A MAIN AUX.
COMPONENT LIST ITEM
NAME
432E
PUMP or MOTOR
434E
442E
1
PUMP GP.
267-2755
2
HYDRAULIC TANK
246-5286
3
TANK GROUP
4
COOLER
5
FILTER
6
HMU
CONTROL VALVES
SPRING
FLUID CONDITIONER
LINE RESTRICTION (FIXED)
RESTRICTION
PUMP: VARIABLE and PRESSURE COMPENSATED
2-SECTION PUMP
444E
A
PRESSURE COMPENSATION
LINE RESTRICTION (VARIABLE)
SPRING (ADJUSTABLE)
VARIABILITY
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
ATTACHMENT
LINE RESTRICTION VARIABLE and PRESSURE COMPENSATED
VALVES
245-8777 VALVE ENVELOPES
HYDRAULIC COOLER
VALVE PORTS
226-9747 210-6240
TWO POSITION
ONE POSITION
TWO-WAY
THREE POSITION
FOUR-WAY
THREE-WAY
STEER CYLNDERS
7
7A 7B
CONTROL VALVES
214-5097
FRONT
B
238-5238
REAR
CHECK VALVES
AB
AB
LIFT CYLNDERS
8 9
8B
PL/IT
214-9373
9B
PL/IT
10
MP BUCKET CYL.(OPT)
249-6710 LH 249-6711 RH
249-6712 LH 249-6713 RH
210-7101
214-9372
TILT CYLNDERS
11A
LH
11B
RH
N/A
This illustration shows the optional powered sideshift attachment. The powered sideshift moves the backhoe across the slider using two hydraulic cylinders (A). Wear pads (B) on the slider and powered sideshift assembly are serviceable.
173-4565
12
BOOM CYLINDER
13
STICK CYL.
14
SWING
268-9051(S) 246-9884 210-7093
268-9049(S) 210-7076 210-7083
268-9051(S) 246-9884 210-7093
D
PRESSURE
432E, 434E, 442E, and 444E Backhoe Loader Hydraulic System
C
210-7095(S)
210-7085(S)
15
BUCKET CYL.
16
E-STICK CYL (OPT).
17A
VALVE PILOT-BODY
223-4713
17B
LEVER W/SWITCHES
223-4714
17C
210-7095(S)
210-7097(S) VALVE PILOT 2-BANK
17
LEVER W/DTNT & SWTCH (OPT)
223-4715
18
ACCUMULATOR
226-0420
19
RIDE CNTRL VALVE (OPT)
245-8780
20
RIDE CNTRL ACCMLTR (OPT)
162-3960
21
RIDE CNTR PRES. SWTCH(OPT)
131-9203
22
TEMP. SENSOR (OPT)
23
DIFF. PRES. SWITCH (OPT)
432E: BXE1-2199
231-2615
COUPLER CYLINDER (See Volume 2)
190-3085
INLET SECTION OUTLET MANIFOLD
266-2562
3 BANK
266-2563
28B
LIFT SECTION
28C
TILT SECTION
28D
SOLENOID
442E: GKZ1-599
29A 29C
RETURN BELOW FLUID LEVEL
SERVO
SOLENOID and PILOT or MANUAL
SOLENOID and PILOT
DETENT
THERMAL
MANUAL CONTROL SYMBOLS
MANUAL SHUTOFF
EXTERNAL RETURN
GENERAL MANUAL
PUSH BUTTON
PEDAL
SPRING
REMOTE SUPPLY PRESSURE
INTERNAL RETURN
SIMPLIFIED
CROSSING AND JOINING LINES
ACCUMULATORS
SPRING LOADED
GAS CHARGED
LINES CROSSING
INTERNAL SUPPLY PRESSURE
COMPLETE
HYDRAULIC AND PNEUMATIC CYLINDERS
SINGLE ACTING
LINES JOINING
DOUBLE ACTING
N/A N/A
To Wheel Brake
269-1081 269-1082
To Tank
HYDRAULIC PUMPS
From Pilot Accumulator
FIXED DISPLACEMENT
N/A
INTERNAL PASSAGEWAYS
HYDRAULIC MOTORS
VARIABLE DISPLACEMENT NON-COMPENSATED
FIXED DISPLACEMENT
VARIABLE DISPLACEMENT NON-COMPENSATED
269-1083
AUX SECTION LOADER VALVE (EST)
29
SOLENOID or MANUAL
444E: LBE1-599
SIDESHIFT
269-1079 LOADER VALVE (PL/IT)
28
RETURN ABOVE FLUID LEVEL
PRESSURIZED
COMBINATION CONTROLS
"E" Series sideshift machines have a new slide frame with new externally serviceable slide frame lock cylinders and reversible/replaceable wear plates (C). The lock cylinders can be serviced in the field with standard tools. The stabilizers (D) are now externally adjustable. A powered sideshift (bottom right illustration) is available, which allows the operator to hydraulically shift the backhoe across the slider.
N/A
269-1080
2 BANK
BIDIRECTIONAL
PILOT CONTROL SYMBOLS 256-3089 (STD)
COUPLER VALVE (See Volume 2)
UNIDIRECTIONAL
RELEASED PRESSURE
256-3089 (OPT)
ALL WHEEL STEER VALVE
27E
434E: FSH1-899
VENTED
134-0404
25
27A
FLOW
TEMPERATURE
PUSH-PULL LEVER
LOADER VALVE (ST)
27
ROTATING SHAFTS
TEMP SENSOR
24 26
PILOT CONTROLLED
FLUID STORAGE RESERVOIRS
278-1971
CYL. 210-7085(S)
SHUTTLE
SPRING LOADED
BASIC SYMBOL
MP BUCKET CYL. 173-4565
268-9049(S) 210-7076 210-7083
INFINITE POSITION
MEASUREMENT
192-3884 STABILIZER CYLNDERS
11
P T SHIFTED POSITION
P T NORMAL POSITION
2 BANK
N/A
266-2572
3 BANK
N/A
266-2573
INLET SECTION
N/A
269-1100
TILT SECTION
N/A
269-1102
UNIDIRECTIONAL
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
CROSS FLOW
PARALLEL FLOW
FLOW IN ONE DIRECTION
TWO POSITION
THREE POSITION
INFINITE POSITIONING
FLOW ALLOWED IN EITHER DIRECTION
BACKHOE VALVE (SIDE SHIFT) 266-2566
7 BANK
266-2567
8 BANK
266-2568
31G
BOOM SECTION
269-1071
31H
STICK SECTION
269-1072
31J
E-STICK SECTION
269-1077
31K
OUTLET MANIFOLD
269-1069
32A
INLET MANIFOLD
269-1060
32B
STABILIZER SECTION
269-1061
32C
SWING SECTION
269-1064
32D
BUCKET SECTION
269-1065
32E
AUX SECTION
269-1067
32F
PATTERN SWITCHING VALVE
257-7724
Slave Cylinder
Master Cylinder
The pilot manifold can also be accessed with the floor plate removed. The pilot pressure tap (T3) is located on the pilot manifold. The pilot manifold routes pilot oil to and from the loader and backhoe pilot control valves.
Boost Brake Valve
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.
BACKHOE VALVES (COMMON)
32
Printed in U.S.A.
© 2008 Caterpillar All Rights Reserved
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.
Pilot Manifold
Electrical Symbols Table Hydraulic Symbols (Electrical)
T3 View of pilot controlled backhoe valve with floor plate removed.
G
206-3685 (OPT)
33
VALVE GP - CUSHION RELIEF
34
VALVE GP - PILOT (BACKHOE)
267-2758
35
VALVE GP - PILOT (LOADER)
267-2760
36
MANIFOLD - PILOT
268-0094
A
B
C
D
E
G
F
I
H
Transducer (Fluid)
J
Transducer (Gas / Air)
M
Generator
Electric Motor
Temp Sensor
Filter Bypass Switch
TAP LOCATIONS L
Tap T1 T2 T3
Pump Discharge Load Sense Pilot Pressure
SOS
A
E
D
C
B
Electrical Symbols (Electrical)
HYDRAULIC OIL FILTER
5
The brake boost valves are connected to the master cylinder (A) at each brake pedal (B). Oil enters the master cylinder through the supply hose (C) and exits the master cylinder through the return hose (D). The oil flows to the service brakes through the hoses (E) at the bottom of the master cylinder.
T
Pressure Symbol
The master cylinders can be removed from the machine from inside the operator's compartment.
36 32 14
31 30 18
Flow Symbol
Level Symbol
Temperature Symbol
22 29 28 23 27 5
11
21 20 19
2
9
8
7
4
M
BOOSTED BRAKES
10
Wire Number Identification Codes
33
Electrical Schematic Example
SOS
13
Implement and Steering Pump
B
16 15
Implement and Steering Pump
K
N
A
EIGHT BANK VALVE (PILOT OPERATED)
Loader Valve
Harness identification code This example indicates wire 135 in harness "AG".
34
13
7
35 17
34
1
35 17
6
9
8
1
10
9
2
25 26
325-PK
(H) Stick Control Valve (I) Boom Control Valve (J) Pilot On/Off Solenoid Valve (K) Inlet Manifold (L) A Ports (M) B Ports (N) Solenoid for the Sideshift Lock
H
C
J
L
K
H
Wire Color
Wire
D E
325-PK-14
B
For other bank valve configurations see RENR6487 (Specifications Manual).
BACKHOE VALVE
Wire Gauge
G
4
T2
Wire Color
Previous Standard
B
A
C
Wire Color
325-AG135 PK-14
14 (A) Outlet Manifold (B) Auxiliary Control Valve (C) Extendable Stick Control Valve (D) Bucket Control Valve (E) Swing Control Valve (F) Left Stabilizer Control Valve (G) Right Stabilizer Control Valve
Wire Circuit Number Identification
Circuit Identification Number
11
Current Standard
Loader Valve
This illustration shows a eight bank backhoe valve in a 420E Backhoe Loader. The components in the backhoe valve are:
12
Hydraulic Schematic Example
Current Standard
Hydraulic Oil Filter
The 420E/430E machines are equipped with a pilot controlled backhoe valve that is visible with the floor plate at the rear of the cab removed.
16 15
Electrical Wire
Temperature Switch
Temp Sensor
Filter Bypass Switch
SOS
The 432E, 434E, 442E and 444E machines are equipped with hydraulically assisted master cylinders, which decreases the amount of pedal effort when braking. This illustration shows the boosted brakes valve group, which uses oil from the pilot accumulator to add boost to the master cylinder. The hydraulic force multiplies the pedal effort so the operator can get more braking force with less effort.
Oil Sampling
Pressure Switch (Adjustable)
Pressure Switch
Description
B
C
30 31 32
D
Circuit Number Identification
A
Wire Gauge (EXAMPLE VALVE)
E
P
The implement and steering pump on the 432E, 434E, 442E and 444E machines is similar to the "D" Series machines, but now includes a torque control solenoid (not visible). The torque control solenoid provides an additional pump setting.
12 14 33
11
31 30 18 36 32
7
22 27 5
21 20 19
6
8
7
23 29 28
10 25 26
The implement and steering pump is located below the floor plate in the cab. The pump control valve (H) contains a torque control spool adjustment screw (B) and a flow compensator adjustment screw (A). The adjustment screws and the load sensing pressure tap (T2) are accessible from the cab.
R
A D
T2
N
F
T2
The 432E/434E/442E and 444E machines are all equipped with the pilot controlled loader valve as shown in this illustration.
Drain
T1
T1 E
E G These illustrations show the implement and steering pump out of the machine. The following components are visible:
View of mechanically controlled loader valve with floor plate removed.
Torque control adjustment (A), Flow compensator adjustment (B), Load sensing pressure tap (T2), Inlet port (C), Case drain port (D), Torque control solenoid (E), Discharge pressure tap (T1), Torque limiter (F), Outlet port (G)
NOTE: Alpha numeric numbers are represented by the number only on the machine views.
COMPONENT LOCATIONS
IMPLEMENT / STEERING PUMP
1
For other bank valve configurations see RENR6487 (Specifications Manual).
Outlet manifold (A) Auxiliary control valve (B) Tilt control valve (C) Lift control valve (D) Inlet manifold (E) Load sensing relief valve (F) Solenoid for the B circuit (G)
LOADER VALVE
27 28 29
Solenoid for the A circuit (H) Makeup and relief valve (J) B pilot line port (K) A pilot line port (L) Priority Valve (M) Dead engine lower valve (N) A ports (P) B ports (R)
Travel at high speeds over rough terrain causes bucket movement. The optional Ride Control System acts as a shock absorber by absorbing bucket forces, which stabilize the machine. The Ride Control System components include; ride control relay (A), ride control solenoids (B), ride control accumulator (C), and ride control pressure switch (D). Two solenoids are now used on the "E" Series machines Ride Control System.
The loader valve is accessed from below the floor plate. The loader control valve group contains:
C
D
A
THREE BANK VALVE (PILOT OPERATED)
B C
M
B
F
D
The Ride Control System, on machines with the optional autoshift transmission, is controlled by the Machine ECM. The Machine ECM monitors the position of the ride control switch and determines when to operate the ride control system.
C
ECM
RIDE CONTROL 16
17 18
RENR6484-03
SOS
30 Page, (Dimensions: 39 inches x 28 inches)
31
6 BANK