SENR4778-02 FLUID POWER SYMBOLS
October 1993 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
966F & 966F Series II Wheel Loaders RETURN ABOVE FLUID LEVEL
Hydraulic System
VENTED PRESSURIZED RETURN BELOW FLUID LEVEL
COMBINATION CONTROLS
1SL1-UP SOLENOID SOLENOID SOLENOID SOLENOID and SERVO THERMAL DETENT
3XJ1-UP or MANUAL and PILOT PILOT or MANUAL
4YG1-UP MANUAL CONTROL SYMBOLS
8BG1-UP
9YJ1-UP PUSH-PULL LEVER MANUAL SHUTOFF GENERAL MANUAL PUSH BUTTON PEDAL SPRING
PILOT CONTROL SYMBOLS
RELEASED PRESSURE REMOTE SUPPLY PRESSURE
EXTERNAL RETURN INTERNAL RETURN SIMPLIFIED COMPLETE INTERNAL
SUPPLY PRESSURE
ACCUMULATORS CROSSING AND JOINING LINES HYDRAULIC AND PNEUMATIC CYLINDERS
SPRING LOADED GAS CHARGED LINES CROSSING LINES JOINING SINGLE ACTING DOUBLE ACTING
HYDRAULIC PUMPS HYDRAULIC MOTORS INTERNAL PASSAGEWAYS
FIXED VARIABLE DISPLACEMENT FIXED VARIABLE DISPLACEMENT THREE TWO
INFINITE
DISPLACEMENT NON-COMPENSATED DISPLACEMENT NON-COMPENSATED POSITIONING POSITION POSITION
UNIDIRECTIONAL UNIDIRECTIONAL
FLOW IN ONE PARALLEL CROSS FLOW ALLOWED IN
BIDIRECTIONAL BIDIRECTIONAL DIRECTION FLOW FLOW EITHER DIRECTION
© 1993 Caterpillar Printed in U.S.A.
All Rights Reserved
SENR4778-02
12 Page
SENR4778-02
12 Page
THIS SCHEMATIC IS FOR THE 966F AND 966F SERIES II WHEEL LOADERS
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
