This document provides symbols for basic components of fluid power systems, including pumps, motors, valves, reservoirs, shafts, and controls. It shows symbols for variable pumps, fluid conditioners, control valves, restrictions, pressure compensation, measurements, storage reservoirs, combination controls, solenoids, manual controls, and pilot controls. The symbols are used to diagram hydraulic and pneumatic systems.

1. SENR8563-01 FLUID POWER SYMBOLS
October 2006 BASIC COMPONENT SYMBOLS
MAIN AUX.
PUMP: VARIABLE and
PUMP or MOTOR FLUID CONDITIONER SPRING CONTROL VALVES RESTRICTION LINE RESTRICTION 2-SECTION PUMP PRESSURE COMPENSATED
(FIXED)
VARIABILITY SPRING LINE RESTRICTION PRESSURE HYDRAULIC PNEUMATIC LINE RESTRICTION ATTACHMENT
(ADJUSTABLE) (VARIABLE) COMPENSATION ENERGY TRIANGLES VARIABLE and PRESSURE
COMPENSATED
VALVES
VALVE ENVELOPES VALVE PORTS
ONE POSITION TWO POSITION THREE POSITION TWO-WAY THREE-WAY FOUR-WAY
CONTROL VALVES CHECK VALVES
AB AB
P T P T
BASIC SPRING SHUTTLE PILOT
NORMAL POSITION SHIFTED POSITION INFINITE POSITION
SYMBOL LOADED CONTROLLED
MEASUREMENT ROTATING SHAFTS
PRESSURE TEMPERATURE FLOW UNIDIRECTIONAL BIDIRECTIONAL
FLUID STORAGE RESERVOIRS
14H Motor Grader
Hydraulic System
VENTED PRESSURIZED RETURN ABOVE FLUID LEVEL RETURN BELOW FLUID LEVEL
COMBINATION CONTROLS
7WJ1-663
SOLENOID SOLENOID SOLENOID SOLENOID and SERVO THERMAL DETENT
or MANUAL and PILOT PILOT or MANUAL
MANUAL CONTROL SYMBOLS
PUSH-PULL LEVER MANUAL SHUTOFF GENERAL MANUAL PUSH BUTTON PEDAL SPRING
PILOT CONTROL SYMBOLS
RELEASED PRESSURE REMOTE SUPPLY PRESSURE
Attachment Circuits
EXTERNAL RETURN INTERNAL
Machine Location Schematic INTERNAL RETURN SIMPLIFIED COMPLETE
SUPPLY PRESSURE
Item No. Component Description Location ACCUMULATORS CROSSING AND JOINING LINES HYDRAULIC AND PNEUMATIC CYLINDERS
19 Plow/Dozeer Control Valve With Float B-1
20 Plow/Dozer Control Valve Without Float B-1 SPRING LOADED GAS CHARGED LINES CROSSING LINES JOINING SINGLE ACTING DOUBLE ACTING
21 Snow Wing Toe Tilt Control Valve B-2
22 Snow Wing Heel Lift Control Valve B-3 HYDRAULIC PUMPS HYDRAULIC MOTORS INTERNAL PASSAGEWAYS
23 Blade Lift Control Valve B-5,B-6
FIXED VARIABLE DISPLACEMENT FIXED VARIABLE DISPLACEMENT THREE TWO
INFINITE
24 Ripper Control Valve B-5,B-6 DISPLACEMENT NON-COMPENSATED DISPLACEMENT NON-COMPENSATED POSITIONING POSITION POSITION
25 Ripper Cylinder D-6 UNIDIRECTIONAL UNIDIRECTIONAL
26 Accumulators For The Blade Cushion D-4
27 Mounting Valves For The Blade Cushion D-4 BIDIRECTIONAL BIDIRECTIONAL
FLOW IN ONE
DIRECTION
PARALLEL
FLOW
CROSS
FLOW
FLOW ALLOWED IN
EITHER DIRECTION
28 Check Valve For Supplemental Steering B-4
29 Electric Drive Pump For Supplemental Steeirng B-3
30 Check Valve For Supplemental Steering B-4
31 Relief Valve For Supplemental Steering B-4 © 2006 Caterpillar Printed in U.S.A.
All Rights Reserved
Electrical Symbols Table
6 5 4 3 2 1
Hydraulic Symbols (Electrical)
G M
D D Transducer Transducer Generator Electric Motor
25 (Fluid) (Gas / Air)
(Dimensions: 24 inches x 34 inches)
26 27 26 27
Pressure Switch Temperature Switch Electrical Wire
SENR8563-01
Pressure Switch
(Adjustable)
Electrical Symbols (Electrical)
C C
C1 C2
T
Pressure Temperature Level Flow
Symbol Symbol Symbol Symbol
23 24 23 22 21 20 19 Wire Number Identification Codes
Electrical Schematic Example Hydraulic Schematic Example
B
30 29 B
Current Standard Current Standard
Harness identification code
S2 V1 This example indicates
wire 135 in harness "AG". Wire
Circuit Number Wire Color
16 Page,
31 325-AG135 PK-14
Identification
325-PK
M Circuit Identification
Number
Wire Color Wire Gauge
Previous Standard
28 1 T1 T2
Wire
Wire Color
A A 325-PK-14
B A
Circuit Number Wire Gauge
Identification (EXAMPLE VALVE)
D14497
6 5 4 3 2 1

2. 15
18
13 14
6 5 4 3 2 1
8 12
25 26 10
F
9 11
F
6 22 8
8 12 8 23 9
13 14 17 18 5 17
27 28
11
29 30
2 7 19
E 10 E 3 4
1 20 21
16
16 22
C2
C1
16 16 D17025
15 24
5
D
6 7 D
C C
S2
(Dimensions: 24 inches x 34 inches)
MAIN CONNECTOR LINE
PILOT LINE
SENR8563-01
DRAIN LINE
S1
B B
Hydraulic System For Implement And Steering Circuits
Machine Location Schematic
Item No. Component Description Location
4
1 Filter & Tank B-6
1 2
3
Piston Pump
Combination valve
A-4
A-3
4 Steering Accumulator B-3
5 Metering Pump For Steering D-3
6 Left Implement Valve Group D-6
7 Right Implement Valve Group D-3
8 Cylinder For Blade Lift F-2,F-6
9 Cylinder For Side Shift F-6
10 Swivel Group E-6
16 Page, Color 2,
11 Cylinder For Blade Tip F-5
12 Gerotor Motor For Circle Drive E-5
T1 T2 13 Left Steering Cylinder F-4
3
14 Right Steering Cyliinder F-4
15 Relief Valves For Steering Cylinders E-4
A V1 A 16 Left And Right Articulation Cylinders E-4
17 Centershift Cylinder F-3
2 18 Wheel Lean Cylinder F-3
D14496
6 5 4 3 2 1
THIS SCHEMATIC IS FOR THE 14H
Components are shown installed on a fully operable machine with the key and engine
off and transmission shifter in neutral.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations