Plano Hidraulico Cat 994F

B

C

D

E

F

RENR6320 July 2005
KK J HH A JJ 3 4 5

FLUID POWER SYMBOLS
BASIC COMPONENT SYMBOLS
MAIN AUX.

PUMP or MOTOR

FLUID CONDITIONER

SPRING

CONTROL VALVES

RESTRICTION

LINE RESTRICTION (FIXED)

2-SECTION PUMP

PUMP: VARIABLE and PRESSURE COMPENSATED

G H FF

GG

6

VARIABILITY

SPRING (ADJUSTABLE)

LINE RESTRICTION (VARIABLE)

PRESSURECOMPENSATION

HYDRAULIC PNEUMATIC ENERGY TRIANGLES

LINE RESTRICTION
VARIABLE and PRESSURE COMPENSATED

ATTACHMENT

1 9 EE 8 DD CC
AB

VALVE ENVELOPES

VALVES

VALVE PORTS

7
ONE POSITION TWO POSITION THREE POSITION TWO-WAY THREE-WAY
FOUR-WAY

2

CONTROL VALVES
AB

CHECK VALVES

P T NORMAL POSITION

P T SHIFTED POSITION

INFINITE POSITION

BASIC SYMBOL

SPRINGLOADED

SHUTTLE

PILOT CONTROLLED

MEASUREMENT
LL
The steering system is made up of the following components that are located on the rear frame (A). - Neutralizers and quad check valves (B) - High pressure screens (C) - Steering Valves (control and reducing) (D) - Case drain filters (E) - Steering and brake hydraulic tank (F) - Right steering cylinder (G) - Left steering cylinder (H) -Steering pumps (J)
PRESSURE TEMPERATURE FLOW UNIDIRECTIONAL

ROTATING SHAFTS

BIDIRECTIONAL

The power train hydraulic system is equipped with remote pressure taps. The remote pressure taps are located in the service bay, behind the cab. The remote pressure taps are:

994F Wheel Loader Hydraulic System
442 1-UP

FLUID STORAGE RESERVOIRS

VENTED

PRESSURIZED

RETURN ABOVE FLUID LEVELRETURN BELOW FLUID LEVEL

COMBINATION CONTROLS

SOLENOID

SOLENOID or MANUAL

SOLENOID and PILOT

SOLENOID and PILOT or MANUAL

SERVO

THERMAL

DETENT

MANUAL CONTROL SYMBOLS

Steering System

ON THIS SCHEMATIC: (KK) - Rear brake pressure (JJ) - Front brake pressure (HH) - Brake cooling pump pressure (GG)- Front brake accumulator pressure

ADDITIONAL:
(THESE TAPS ARE NOTREFERENCED ON THIS SCHEMATIC)

PUSH-PULL LEVER

MANUAL SHUTOFF

GENERAL MANUAL

PUSH BUTTON

PEDAL

SPRING

(1) - Implement pilot pressure (2) - Implement cooling pump pressure (3) - Speed clutch pressure (4) - Directional clutch pressure (5) - Torque converter inlet pressure (6) - Torque converter outlet pressure (7) - Lock-up clutch control pressure (8) - Impeller clutch controlpressure (9) - Transmission lube pressure
SPRING LOADED GAS CHARGED EXTERNAL RETURN INTERNAL RETURN

PILOT CONTROL SYMBOLS
RELEASED PRESSURE REMOTE SUPPLY PRESSURE

Tap Locations Pressure, Sampling, and Sensor
Tap Number
AA BB CC DD EE FF GG HH JJ KK LL

(FF) - Rear brake accumulator pressure (CC) - Left steering pump pressure (DD) - Right steering pump pressure (EE) - Steering cooling pumppressure (LL) - Transmission fluid sampling port (S•O•S)

SIMPLIFIED

COMPLETE

INTERNAL SUPPLY PRESSURE

Description
STEERING CYLINDER PRESSURE (LEFT) STEERING CYLINDER PRESSURE (RIGHT) LEFT STEERING PUMP PRESSURE RIGHT STEERING PUMP PRESSURE STEERING COOLING PUMP PRESSURE REAR BRAKE ACCUMULATOR PRESSURE FRONT BRAKE ACCUMULATOR PRESSURE BRAKE COOLING PUMP PRESSURE FRONT BRAKE PRESSUREREAR BRAKE PRESSURE OIL SAMPLE PORT (SOS)

Schematic Location
E-8 E-8 C-7 D-5 C-3 E-1 E-1 B-2 D-2 D-2 C-3

ACCUMULATORS

CROSSING AND JOINING LINES

HYDRAULIC AND PNEUMATIC CYLINDERS

LINES CROSSING

LINES JOINING

SINGLE ACTING

DOUBLE ACTING

HYDRAULIC PUMPS
FIXED DISPLACEMENT VARIABLE DISPLACEMENT NON-COMPENSATED

HYDRAULIC MOTORS
FIXED DISPLACEMENT VARIABLE DISPLACEMENTNON-COMPENSATED

INTERNAL PASSAGEWAYS
INFINITE POSITIONING THREE POSITION TWO POSITION

UNIDIRECTIONAL

UNIDIRECTIONAL
FLOW IN ONE DIRECTION PARALLEL FLOW CROSS FLOW FLOW ALLOWED IN EITHER DIRECTION

BIDIRECTIONAL

BIDIRECTIONAL

Volume 1: Steering and Brake System
PRESSURE TAPS
© 2005 Caterpillar All Rights Reserved

Printed in U.S.A.

Component Locations
Item Number
1 2 3...