INTERACTIVE SCHEMATIC

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EC-C2 E-C60 this interactive schematic
EC-C3
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E-C61

VIEW ALL CALLOUTS

EC-C1
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machine view, clicking on this button will
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underlined. These are hyperlinks button is located in the top right corner
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schematic and machine views.

ELECTRICAL SYMBOLS BASIC HYDRAULIC

HOTKEYS (Keyboard Shortcuts) COMPONENT SYMBOLS
T

Pressure Temperature Level Flow

Pump

FUNCTION KEYS
Switch Switch Switch Switch Circuit Breaker
or Motor Variability

Click here to view the

Zoom In “CTRL” / “+” Schematic Symbols
Fluid
Conditioner
Spring
(Adjustable)

Zoom Out “CTRL” / “-” and Definitions page

Fit to Page “CTRL” / “0” (zero)

Hand Tool “SPACEBAR” (hold down)
Find “CTRL” / “F”
Search “CTRL” / “SHIFT” / “F”
SCHEMATIC SYMBOLS AND DEFINITIONS

VALVES INTERNAL PASSAGEWAYS PUMPS BASIC HYDRAULIC

ENVELOPES FLOW IN ONE
DIRECTION
FLOW ALLOWED IN
EITHER DIRECTION
PARALLEL
FLOW
CROSS
FLOW
FIXED DISPLACEMENT
COMPONENT SYMBOLS

One Position Two Position Three Position Unidirectional Bidirectional Pump

Infinite Two Three Variability
Positioning Position Position or Motor
PORTS VARIABLE DISPLACEMENT
NON- COMPENSATED

CYLINDERS Fluid Spring

(Adjustable)
Two-way Three-Way Four-Way Conditioner
Unidirectional Bidirectional
CONTROL
AB AB
Single Acting Double Acting
MOTORS Pressure
FIXED DISPLACEMENT Spring
P T P T Compensation
Normal Position Shifted Position Infinite Position

CHECK
Control
ACCUMULATORS Unidirectional Bidirectional
Valves
Line Restriction
(Variable)
VARIABLE DISPLACEMENT
Basic Spring Shuttle NON- COMPENSATED
Pilot
Symbol Loaded Line Restriction
Controlled Spring Loaded Gas Charged Restriction
(Fixed)

Unidirectional Bidirectional

MAIN AUX.
Line Restriction
PILOT CONTROL 2-Section
RELEASED PRESSURE ROTATING SHAFTS Variable and Pressure
Compensated
Pump

Unidirectional Bidirectional
External Return Internal Return
Attachment Pump: Variable and
REMOTE SUPPLY PRESSURE Pressure Compensated

Internal Hydraulic Pneumatic

Simplified Complete Supply Pressure Energy Triangles

COMBINATION CONTROLS
LINES MEASUREMENT

Solenoid Solenoid Solenoid Solenoid and Servo Thermal Detent Crossing Joining
or Manual and Pilot Pilot or Manual Pressure Temperature Flow

MANUAL CONTROL FLUID STORAGE RESERVOIRS

Push-pull Lever Manual Shutoff General Manual Push Button Pedal Spring Vented Pressurized Return Above Fluid Level Return Below Fluid Level

HYDRAULIC SYMBOLS - ELECTRICAL ELECTRICAL SYMBOLS

G
M T

Pressure Temperature Level Flow

Transducer Transducer Generator Electric Pressure Pressure Switch Temperature Electrical
Switch Switch Switch Switch Circuit Breaker
(Fluid) (Gas / Air) Motor Switch (Adjustable) Switch Wire

BASIC ELECTRICAL COMPONENT SYMBOLS HARNESS AND WIRE SYMBOLS

Wire, Cable, or Harness Assembly Identification:
Fuse: A component in an electrical circuit that will open the circuit if too much current flows through it. Includes Harness Identification Letters and Harness
Connector Serialization Codes (see sample).
Switch (Normally Open): A switch that will close at a specified point (temp, press, etc.). The circle indicates
that the component has screw terminals and a wire can be disconnected from it.
AG-C4 L-C12
Switch (Normally Closed): A switch that will open at a specified point (temp, press, etc.). 111-7898 3E-5179
No circle indicates that the wire cannot be disconnected from the component. Part Number: for 1
Connector Plug
Ground (Wired): This indicates that the component is connected to a grounded wire. 2
The grounded wire is fastened to the machine.
Plug Receptacle
Pin or Socket Number
Ground (Case): This indicates that the component does not have a wire connected to ground.
It is grounded by being fastened to the machine. Harness Identification Letter(s): (A, B, C, AA, AB, AC, ...)

Reed Switch: A switch whose contacts are controlled by a magnet. A magnet closes the contacts of Harness Connector Serialization Code: The "C" stands for
"Connector" and the number indicates which connector in the
a normally open reed switch; it opens the contacts of a normally closed reed switch.
harness (C1, C2, C3, ...)
L-C12
Sender: A component that is used with a temperature or pressure gauge. 3E-5179
The sender measures the temperature or pressure.
T Its resistance changes to give an indication to the gauge of the temperature or pressure. 5A
Component
Relay (Magnetic Switch): A relay is an electrical component that is activated by electricity. Fuse (5 Amps) 9X-1123 Part Number
It has a coil that makes an electromagnet when current flows through it.
The electromagnet can open or close the switch part of the relay. 325-AG135 PK-14
Harness identification code:
This example indicates wire group 325, Wire Gauge
Solenoid: A solenoid is an electrical component that is activated by electricity. wire 135 in harness "AG". Wire Color
It has a coil that makes an electromagnet when current flows through it.
The electromagnet can open or close a valve or move a piece of metal that can do work. 1 Deutsch connector: Typical representation
of a Deutsch connector. The plug contains all
2 sockets and the receptacle contains all pins.
Magnetic Latch Solenoid: An electrical component that is activated by electricity and held latched by a
permanent magnet. It has two coils (latch and unlatch) that make electromagnet 1 Sure-Seal connector: Typical representation
when current flows through them. It also has an internal switch that places of a Sure-Seal connector. The plug and receptacle
2 contain both pins and sockets.
the latch coil circuit open at the time the coil latches.
 UENR7442-01
November 2016

D8R and D8T Track-Type Tractor

Power Train System
D8R2: D8T:
DWJ1-UP JJ51-UP
JR8-UP MB81-UP

©2016 Caterpillar CAT, CATERPILLAR, their respective logos, “Caterpillar Yellow”, and the POWER EDGE trade dress as well as
All Rights Reserved corporate and product identity used herein, are trademarks of Caterpillar and may not be used without permission.
COMPONENT LOCATION

Part Machine Schematic

Description
Number Location Location
Breather As 9G-5127 1 B-4
Core Gp - Oil Cooler 4W-9822 2 C-1
Filter Gp - Oil 332-8833 3 A-4
Left Drive / Brake Gp 464-8229 4 F-5
Plate - Orifice 489-0223 5 B-4
Power Train Oil Pump (3 Section) 455-9638 6 C-3
Right Drive / Brake Gp 464-8230 7 B-5
Torque Converter & Housing Gp 387-5630 8 E-2
Transmission Ar 384-4149 9 D-6
Valve Gp - Brake Control 485-5146 10 E-4
Valve Gp - Relief (Torque Converter Outlet) 208-3019 11 D-2
TAP LOCATION

Tap Schematic
Description
Number Location
B1 Brake Pressure - Left E-4
B2 Brake Pressure - Right E-4
L2 Flywheel Lube Pressure C-2
LB1 Left Brake Lube Pressure F-5
LB2 Right Brake Lube Pressure B-5
N Torque Converter Outlet Pressure D-2
M Torque Converter Supply Pressure C-3
L1 Transmission Lube Pressure E-6
P1 Transmission Main Relief Pressure D-6
 7 6 5 4 3 2 1

LB1
(4) LEFT DRIVE AND BRAKE GP
464-8229

LUBE BRAKE

F F

B1
HYDRAULIC
PUMP
L1 STACK

LA
ELECTRONIC

E N
LV TIO
BRAKE VALVE (10) VALVE GP - BREAK CONTROL

VA OR
NOTE C 485-5146

P
O
PR
E E

(8) TORQUE CONVERTER GP

XMSN LUBE
387-5630

B2 VENT LINE

REAR GEAR
TRAIN LUBE
MAIN RELIEF

BEVEL & TRANSFER

(11) VALVE GP
RELIEF(TORQUE

CONVERTER
GEAR LUBE
DIFF STEER

TORQUE
CONVERTER OUTLET)

FLYWHEEL HOUSING
REAR GEAR TRAIN
208-3019

REV FWD 3RD 2ND 1ST

CL1
N ENGINE
CL2 CL3 CL4 CL5

D D
PROPORTIONAL

PROPORTIONAL
PROPORTIONAL

PROPORTIONAL

PROPORTIONAL
VALVE

VALVE
VALVE

VALVE

VALVE

SUCTION
SCREEN
ER1

P1

(9) TRANSMISSION AR
384-4149 (6) POWER TRAIN OIL PUMP
SCAVENGE
SCREEN (3 SECTION)
OUTPUT /
DIFF STEER 455-9638
C LUBE C
HYDRAULIC PUMP
STACK

C B A
TORQUE (2) CORE GP - OIL
CONVERTER COOLER
INLET RELIEF 4W-9822

M L2

LUBE DISTRIBUTION
MANIFOLD

(5) PLATE - ORIFICE

BRAKE LUBE 489-0223

LB2
(1) BREATHER AS
B (7) RIGHT DRIVE AND BRAKE GP 9G-5127 B
464-8230

SOS SAMPLING
FILTER ELEMENT PORT
NOTE B
ACCUMULATOR

NOTE A: ALL FLOWS ARE AT RATED ENGINE SPEED OF 1850 RPM WITH THE
FILTER BYPASS
TRANSMISSION IN NEUTRAL. ALL LEAKAGES ARE MAX.
SWITCH
NOTE B: OIL CLEANLINESS MUST MEET ISO SPEC 19/15 AT SHIP.
OIL SAMPLES SHOULD BE TAKEN AT OIL SAMPLING PORT.
FILTER BYPASS
NOTE C: BREATHER IS LOCATED ON THE FILE TUBE
VALVE
(3) FILTER GP - OIL
332-8833
PTO SUMP
TEMP - ECM
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
Brakes.
LINE PATTERNS SECTION A: LUBE Supply Line.
A Pressure Line
SECTION B: CONTROLS Drain / Return Line. A
Transmission Charge Pump.
SECTION C: SCAVENGE
Pilot / Load Sensing Pressure Transmission and Torqueconverter Scavenge Pump
Torque Converter Charge Pump and Powertrain Oil Cooler
Drain / Return Lines
Lubrication and Transmission Oil Cooler Circuit
Component Group

CALLOUTS
THIS SCHEMATIC IS FOR THE D8R AND D8T TRACK TYPE TRACTOR POWER TRAIN SYSTEM
MEDIA NUMBER: UENR7442-01
YY Taps (Pressure, Sampling, Sensor - by letter)
SCHEMATIC PART NUMBER: 483-4995, CHANGE: 00, VERSION: -
Callout Number Component
Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
(Machine Location from (52) VALVE GP - CONTROL Name in neutral and with parking brake set.
Component Locations Table)
138-1234 Part Number Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.

7 6 5 4 3 2 1
MACHINE COMPONENT LOCATIONS
VIEW ALL CALLOUTS
P1 1 LB1 4
9 B1

L1 6

10 5

11
B2

M
LB2

8
7

2
3

N L2