SENR8330
December 1995
FLUID POWER SYMBOLS
BASIC COMPONENT SYMBOLS
MAIN AUX.
PUMP or MOTOR
LINE RESTRICTION
(FIXED)
RESTRICTION
PRESSURE
COMPENSATION
LINE RESTRICTION
(VARIABLE)
SPRING
(ADJUSTABLE)
VARIABILITY
CONTROL VALVES
SPRING
FLUID CONDITIONER
PUMP: VARIABLE and
PRESSURE COMPENSATED
2-SECTION PUMP
HYDRAULIC
PNEUMATIC
ENERGY TRIANGLES
ATTACHMENT
LINE RESTRICTION
VARIABLE and PRESSURE
COMPENSATED
VALVES
VALVE ENVELOPES
VALVE PORTS
TWO POSITION
ONE POSITION
TWO-WAY
THREE POSITION
CONTROL VALVES
No.
1
Steering Motor Group
Steering Pump Group
Steering Pilot Valve Group
Bulldozer Dual Tilt Cylinder Group
Bulldozer Lift Cylinder Group
Quick-Drop Valve
Bulldozer Tilt Cylinder Group
Steering Charge Loop Filter Group
Tank Group
10
Cover
11
Bulldozer Tilt Valve
12
Bulldozer Lift valve
13
Ripper Valve
14
Inlet Manifold
15
Ripper Lift / Tilt Valve
16
Pilot Operated Relief Valve
17
Charging Relief Valve
18
Implement Pump Group
19
Bypass / Pressure Control Valve
20
Cooler
CHECK VALVES
AB
AB
HYDRAULIC SYSTEM COMPONENTS
DESCRIPTION
P T
SHIFTED POSITION
P T
NORMAL POSITION
INFINITE POSITION
PRESSURE
Ripper Tip Cylinder
Ripper Lift Cylinder
23
Ripper Diverter Valve
24
Pin Puller Cylinder
PILOT
CONTROLLED
ROTATING SHAFTS
FLOW
TEMPERATURE
UNIDIRECTIONAL
BIDIRECTIONAL
FLUID STORAGE RESERVOIRS
D8R Track-Type Tractor
Hydraulic System
7XM1-UP
9EM1-UP
VENTED
RETURN ABOVE FLUID LEVEL
PRESSURIZED
RETURN BELOW FLUID LEVEL
COMBINATION CONTROLS
SOLENOID
or MANUAL
SOLENOID
SERVO
SOLENOID and
PILOT or MANUAL
SOLENOID
and PILOT
DETENT
THERMAL
MANUAL CONTROL SYMBOLS
GENERAL MANUAL
MANUAL SHUTOFF
PUSH BUTTON
PEDAL
SPRING
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
22
SHUTTLE
SPRING
LOADED
BASIC
SYMBOL
MEASUREMENT
PUSH-PULL LEVER
21
FOUR-WAY
THREE-WAY
EXTERNAL RETURN
REMOTE SUPPLY PRESSURE
INTERNAL RETURN
SIMPLIFIED
CROSSING AND JOINING LINES
ACCUMULATORS
SPRING LOADED
GAS CHARGED
LINES CROSSING
HYDRAULIC PUMPS
FIXED
DISPLACEMENT
HYDRAULIC AND PNEUMATIC CYLINDERS
SINGLE ACTING
LINES JOINING
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
DOUBLE ACTING
INTERNAL PASSAGEWAYS
HYDRAULIC MOTORS
VARIABLE DISPLACEMENT
NON-COMPENSATED
INTERNAL
SUPPLY PRESSURE
COMPLETE
TWO
POSITION
THREE
POSITION
INFINITE
POSITIONING
PARALLEL
FLOW
FLOW IN ONE
DIRECTION
CROSS
FLOW
FLOW ALLOWED IN
EITHER DIRECTION
Printed in U.S.A.
1995 Caterpillar
All Rights Reserved
Electrical Symbols Table
Hydraulic Symbols (Electrical)
G
Transducer
(Fluid)
Transducer
(Gas / Air)
Generator
Electric Motor
Right Steer Loop (at Motor)
Right Steer Loop (at Pump)
Left Steer Actuator
Right steer Actuator
Left Steer Loop (at Motor)
Left Steer Loop (at Pump)
Charge Pump Relief
Control Supply
Right Steer Pilot
Left Steer Pilot
Ripper Pilot
Case Return
Charge Pump Discharge
Charge Pump Relief
Cooler
Implement Pump Discharge (at Valve)
Implement Pump Signal (at Valve)
Implement Pump Signal
Implement Pump Discharge
Downstream Filter
Pressure Switch
(Adjustable)
Pressure Switch
Electrical Wire
Temperature Switch
Electrical Symbols (Electrical)
Pressure
Symbol
Temperature
Symbol
Flow
Symbol
Level
Symbol
Wire Number Identification Codes
Electrical Schematic Example
Hydraulic Schematic Example
Current Standard
Current Standard
Harness identification code
This example indicates
wire 135 in harness "AG".
Wire
Circuit Number
Identification
Wire Color
325-AG135 PK-14
325-PK
Circuit Identification
Number
Wire Color
Wire Gauge
Previous Standard
Wire Color
Wire
325-PK-14
B
Circuit Number
Identification
Wire Gauge
(EXAMPLE VALVE)
12 Page, DGM
SENR8330-00
PRESSURE TAP LOCATIONS
LETTER
DESCRIPTION
F
3
24
J
E
22
20
5
23
21
R
6
19
L
D
5
22
21
17
16
18
U
S
15
14
12 Page, Color 2, DGM
SENR8330-00
13
7
12
LINE PATTERNS
Pressure Line
Pilot / Load Sensing Pressure
Drain / Return Lines
11
Component Group
Attachment
Air Line
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
10
CALLOUTS
Steering Pump Output.
Implement Pump Output.
Ripper Cylinder Group.
Supply Line.
Drain / Return Line.
Dual Tilt Cylinder Group
YY
Taps (Pressure, Sampling,Sensor) by letter
52
Components by number
Lift Cylinder Group
Tilt Cylinder Group
Steering Pilot Valve Group
Load Sensing
Pin Puller Cylinder
THIS SCHEMATIC IS FOR THE D8R TRACK-TYPE TRACTOR
Components are shown installed on a fully operable machine with the key and engine
off and transmission shifter in neutral.
