RENR8997-04 February 2013
FLUID POWER SYMBOLS
26
BASIC COMPONENT SYMBOLS
28 29
9 35 43 15 16
39
25 30 31
MAIN
46 24 49 23
17
PUMP OR MOTOR
FLUID CONDITIONER
SPRING
CONTROL VALVES
VARIABILITY
SPRING (ADJUSTABLE)
LINE RESTRICTION (VARIABLE)
PRESSURE COMPENSATION
RESTRICTION
LINE RESTRICTION (FIXED)
AUX
PUMP (2 - SECTION)
50
4
27
29
ONE POSITION
TWO POSITION
LOWER, LEFT SIDE, CENTER
THREE POSITION
TWO - WAY
THREE - WAY
FOUR - WAY
CHECK VALVES
A B
P T
P T
NORMAL POSITION
SHIFTED POSITION
BASIC SYMBOL
INFINITE POSITION
SPRING LOADED
SHUTTLE
PILOT CONTROLLED
FLUID STORAGE RESERVOIRS
28 PRESSURIZED
VENTED
938H/IT38H Wheel Loader Hydraulic System
30
48
ATTACHMENT
VALVE PORTS
CONTROL VALVES AB
LINE RESTRICTION (VARIABLE & PRESSURE COMPENSATED)
VALVES
VALVE ENVELOPES
24
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
PUMP (VARIABLE & PRESSURE COMPENSATED)
RETURN ABOVE FLUID LEVEL
RETURN BELOW FLUID LEVEL
MEASUREMENT
PRESSURE
ROTATING SHAFTS
TEMPERATURE
FLOW
UNIDIRECTIONAL
BIDIRECTIONAL
COMBINATION CONTROLS
938H: MCC1-UP MJC1-UP JKM1-UP LKM1-UP
25
IT38H: JNJ1-UP SOLENOID
SOLENOID OR MANUAL
SOLENOID & PILOT
GENERAL MANUAL
MANUAL SHUTOFF
26
G5
EXTERNAL RETURN
44
34 20
22 18
2
21
7
SPRING LOADED
38 41
STEERING COMPONENT LOCATIONS
Component Locations Machine Location
Schematic Location
GAS CHARGED
FIXED DISPLACEMENT
COMPONENT LOCATIONS
Part Number 275-7875
1
C-4, F-3
Accumulator. Gp - Ride Cntrl (Attch)
259-4685
2
D-1, F-1
Cylinder Gp - Lift
254-9037
3
C-3, F-2
Cylinder Gp - Tilt
346-1093 346-1094
4
C-4, F-3
Tilt, High Lift Filter Gp - Pump Case Drain
285-2235
5
C-8
Manidfold Gp - Relief
277-9660
6
D-8
Plate - Orifice
317-5574
7
B-4, F-3
Pump Gp - Implement / Steering
304-9308
8
D-8
Screen
9T-9227
9
Tank Gp - Hydraulic Oil
255-2421
15
C-7 C-7 to C-8 B-6
Valve - Breaker Relief, Vacuum
258-2829
16
C-8
Valve Gp - 2 Function 2 Function w/ Ride Control (Attch) 3 Function (Attch) 3 Function w/ Ride Control (Attch) 4 Function (Attch)
336-3818 336-3819 336-3820 336-3821 336-3822
17
E-1 to F-3 B-1 to B-4
Valve Gp - Ball, Dead Engine
112-1817
18
C-4, F-3
Valve Gp - Mntng, Power Control
286-8970
19
D-7
Valve Gp - Pilot, 2 Funct. (Attch), 1 Joystick Pilot, 2 Funct., 2 Levers Pilot, 3 Funct. (Attch), 1 Joystick Pilot, 3 Funct. (Attch), 3 Levers Pilot, 4 Funct. (Attch), 1 Joystick Pilot, 4 Funct. (Attch), 4 Levers
261-8653 261-8654 261-8655 261-8656 261-8657 261-8658
20
F-5 to F-6
Valve Gp - Ride Cntrl (Attach)
314-4008
21
C-1
245-5943 Steering System
22
C-7
Valve Gp - Tank Drain
314-9340
23
F-8
322-4638
24
F-8
Pump Gp - Sec. Steer (Attch)
313-5855
25
E-8
Screen Gp
306-4025
26
D-8
Valve Gp - Check
128-6847
27
E-8
Valve Gp - Check
303-5974
28
C-8
Valve Gp - Check, Sec. Steer (Attch)
9T-1013
29
E-8
Valve Gp - Priority, Steering
317-0953
30
D-8
31
D-7
Cooler - Oil
282-2024
32
D-6
Filter Gp - Fan Return
244-1031
33
D-6
Manifold Gp - Brake / Fan
309-4907
34
C-6
Motor Gp - Fan Fan, Cold Start Attachment
265-4925 330-0826
35
254-5145
36
C-7
Valve Gp - Ball, Dead Engine
112-1817
37
C-5
Valve Gp - Check
175-0447
38
D-6
Valve Gp - Check, Cooler Bypass
145-8983
39
D-6
Valve Gp - Shutoff (Cold Start Attachment) 332-1166 Axle Hydraulic System (Attachment)
40
D-7
Accmltr. Gp - Diff. Lck. (Attch)
245-2975
41
B-7, F-7
Manifold Gp - Mntng, Man. Frnt Diff. Lck. Mntng, Auto. Frnt / Rear Diff. Lck.
244-7139 244-7140
42
B-7, F-7
Pump Gp - Axle Oil Cooling (Attch)
273-1807
43
E-6
Screen Gp - Magnetic, Front Axle Cooling
251-6351
44
D-6
Screen Gp - Magnetic, Rear Axle Cooling
251-6351
45
E-6
Valve Gp - Relief,Axle Oil Clr Bypass
130-5202
8J-6875 Quick Coupler (Attachment)
46
E-6
47
D-8
Cylinder Gp - Quick Coupler (Attch)
311-1463
48
A-3, D-3
Manifold Gp - Cntrl, Quick Coupler (Attch)
180-8585
49
A-4, D-3
Valve Gp - Ball, Dead Engine
112-1817
50
A-4, D-3
© 2013 Caterpillar, All Rights Reserved
HYDRAULIC MOTORS FIXED DISPLACEMENT
INTERNAL PASSAGEWAYS
VARIABLE DISPLACEMENT NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
DOUBLE ACTING
INFINITE POSITIONING
3 POSITION
FLOW IN ONE DIRECTION
PARALLEL FLOW
CROSS FLOW
16
9
20
G11
36
15
G
G6
33
TRANSDUCER (FLUID)
TRANSDUCER (GAS / AIR)
GENERATOR
ELECTRIC MOTOR
PRESSURE SWITCH
PRESSURE SWITCH (ADJUSTABLE)
TEMPERATURE SWITCH
ELECTRICAL WIRE
38
G2
34
G3
M
G12
ELECTRICAL SYMBOLS (ELECTRICAL)
G8
T
6
PRESSURE SWITCH
G14 G10
19
G1
37 47
39
32 35
G13 RIGHT SIDE, CENTER VIEW
RIGHT SIDE, REAR VIEW
3
4
Fan Motor Supply Pressure
D-7
Fan Pump Load Sense Pressure
C-7
G3
Implement / Steering Pump Load Sense
D-8
ELECTRICAL SCHEMATIC EXAMPLE
HYDRAULIC SCHEMATIC EXAMPLE
CURRENT STANDARD
CURRENT STANDARD
WIRE
CIRCUIT NUMBER IDENTIFICATION
21
48
D-8
G4
Implement / Steering Pump Discharge
G5
Steering Supply Pressure
D-8
G6
Schedule Oil Sampling (SOS)
D-6
G7
Implement Pilot Supply Pressure
43
WIRE
46 CIRCUIT NUMBER IDENTIFICATION
G9
G7
7
G8
Brake Accumulator Pressure
D-6
Implement Supply Pressure
E-3, B-4
G10
Fan / Brake Pump Discharge Pressure
C-7
G11
Implmnt / Str Pump Case Drain Airbleed
C-8
G12
Fan Motor Case Drain Airbleed
D-6
G13
Differential Lock Pressure
F-7
G14
Differential Lock Accumulator Pressure
F-7
WIRE COLOR
WIRE COLOR
WIRE GAUGE
325-PK
17
1
RIGHT SIDE, FRONT
45
IMPLEMENT COMPONENT LOCATIONS
WIRE COLOR
B
325-PK-14
F-3, C-4
G9
CIRCUIT NUMBER IDENTIFICATION
PREVIOUS STANDARD
2
18
FLOW SWITCH
WIRE NUMBER IDENTIFICATION CODES
325-AG135 PK-14
50
LEVEL SWITCH
HARNESS IDENTIFICATION CODE THIS EXAMPLE INDICATES WIRE 135 IN HARNESS “AG”
22
RIGHT SIDE, CENTER VIEW
TEMPERATURE SWITCH
40
Schematic Location
G1
FLOW IN EITHER DIRECTION
HYDRAULIC SYMBOLS (ELECTRICAL)
Tap Location Pressure and Sampling
G2
2 POSITION
ELECTRICAL SYMBOLS TABLE
41 Description
SINGLE ACTING
Printed in U.S.A.
49
Note : Always Check Parts Manuals For Your Specific Machine.
Tap Number
HYDRAULIC & PNEUMATIC CYLINDERS
LINES JOINING
UNIDIRECTIONAL
D-6
Pump Gp - Fan
Valve Gp - Shuttle, Diff. Lck
INTERNAL SUPPLY PRESSURE
FAN / BRAKE COMPONENT LOCATIONS
G4
Cylinder Gp - Steering
8J-6875 Fan / Brake System
COMPLETE
5
Pump Gp - HMU
Valve Gp - Shuttle, Load Sense
LINES CROSSING
VARIABLE DISPLACEMENT NON-COMPENSATED
Implement System Accumulator Gp - Pilot
SIMPLIFIED
CROSSING & JOINING LINES
HYDRAULIC PUMPS
42 47
Description
REMOTE SUPPLY PRESSURE
1
3
33 37
8
SPRING
44
42
G13
G14
DIFFERENTIAL LOCK AND AXLE COOLING COMPONENT LOCATIONS
WIRE GAUGE
A
(EXAMPLE VALVE)
(Dimensions: 39 inches x 28 inches)
36 19
PEDAL
30 Page,
6
DETENT
RENR8997-04
40 45
PUSH BUTTON
INTERNAL RETURN
ACCUMULATORS
32
THERMAL
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
31
SERVO
MANUAL CONTROL SYMBOLS
PUSH - PULL LEVER
23
SOLENOID & PILOT OR MANUAL