Challenger Terra Gator 3244 Chassis. Manual - part 120

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Contents

Challenger

®

Terra Gator 3244

Chassis

SERVICE MANUAL

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07 - Hydraulic

Contents

INTRODUCTION

High-Pressure Fluids  ................................................................................................................................. 7-1

Hydraulic Hoses ......................................................................................................................................... 7-1

Avoid Heating Near Pressurized Fluid Lines  ............................................................................................. 7-2

Theory of Operation ................................................................................................................................... 7-2

Tooling List  ................................................................................................................................................ 7-2

Component Location and Function ............................................................................................................ 7-3

Pressure Measurement  ............................................................................................................................. 7-7

Steering System  .................................................................................................................................. 7-7

Braking System  ................................................................................................................................... 7-8

Adjusting Procedure  Brake System .................................................................................................... 7-8

SCHEMATIC

Hydraulic schematic ................................................................................................................................. 7-11

Priority Valve ............................................................................................................................................ 7-13

Emergency Steering (option)  ................................................................................................................... 7-14

INDEX ......................................................................................................................................................... 7-15

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7-1

Introduction

INTRODUCTION

HIGH-PRESSURE FLUIDS

FIG. 1: AVOID HIGH-PRESSURE FLUIDS

Escaping fluid under pressure can penetrate the skin

causing serious injury.

The vehicle must be stopped and cooled before

checking fluids. Use caution when removing radiator

caps, plugs, grease fittings or pressure taps.

Never open pressure lines when they are under

pressure. Release all pressure before doing

maintenance or repairs on any pressure system.

Avoid the hazard by relieving pressure before

disconnecting hydraulic or other lines. Tighten all

connections before applying pressure.

FIG. 2: Search for leaks with a piece of wood or

cardboard. Protect hands and body from high pressure

fluids. Do not use your hands!

Never open hydraulic lines or fuel lines when they are

under pressure. Hydraulic fluid or diesel fuel under

pressure can cut the skin, cause bad burns, eye injury

or skin irritation.

If an accident does occur, get medical help immediately

if any personnel are injured by hydraulic fluid or fuel.

Any fluid injected into the skin must be surgically

removed within a few hours or gangrene may result.

Doctors unfamiliar with this type of injury should

reference a knowledgeable medical source.

HYDRAULIC HOSES

IMPORTANT: Hydraulic hoses have a limited working

live. By weather influences and use under

heavy conditions and normal aging the

working live reduce.

Therefore is checking of hydraulic hoses by damaging

and aging important for good functioning of your

machine and the safety of the user and the

environment. 

Replace immediately damaged and leaking hydraulic

hoses.

FIG. 1

FIG. 2

Introduction

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AVOID HEATING NEAR PRESSURIZED 
FLUID LINES

FIG. 3: Never heat by welding, soldering or using a

torch near pressurized fluid lines or other flammable

materials.

Pressurized lines can be accidentally cut when heat

goes beyond the immediate flame area.

Flammable spray can be generated by heating near

pressurized fluid lines, resulting in severe burns to

personnel and bystanders.

THEORY OF OPERATION

The steering on the 3244 is hydraulically controlled. A

displacement gear pump draws hydraulic oil from the

reservoir. Hydraulic flow is sent directly to the priority

valve mounted to the side of the right fender

underneath the Cab.

The priority valve direct hydraulic flows out the Control

Flow (CF) port to the steering unit. The steering unit

always has priority over any other function in the

hydraulic system. When the steering unit is not

demanding oil flow, the priority valve shifts to send oil

flow out the Excess Flow (EF) port toward the

application system hydraulics.

As the steering wheel is turned a, load sense signal,

along with a spring, shifts the priority to direct oil flow

out the CF port toward the steering unit. The steering

unit direct hydraulic oil toward one of the steering

cylinders which are attached to the pivot point.

Extending and retracting the steering cylinders pivot the

front chassis in the desired direction. There is one

cylinder mounted to each side of the pivot point. The

cylinders are plumbed so that when one cylinder

retracts, the other extends.

Excess oil flow leaves the EF port of the priority valve

and travels to the application system hydraulic

functions.

Once the hydraulic oil is through the functions, it is

returned to the reservoir through the oil cooler and the

return filter.

TOOLING LIST

For the right tools see, chapter 1; “Tooling List” in the

front of this manual.

FIG. 3

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Introduction

COMPONENT LOCATION AND 
FUNCTION

Component layout:

1. Hydraulic Oil Tank;

2. Hydraulic Gear Pump;

3. Priority Valve;

4. Steering Unit;

5. Steering Cylinder;

6. Hydraulic Oil Cooler;

7. Application System Hydraulics;

8. Pivot Point;

9. 3 Accumulators.

FIG. 4

Q000091S

1

2

3

5

5

5

6

7

8

8

4

4

9