DAF CF65, CF75, CF85 Series . Manual - part 945

©

 200423

1

Contents

DIAGNOSTICS

ΧΦ65/75/85 series

7

1

1 Diagnostics

CONTENTS

Page

Date

1.

STEERING GEAR, GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . 200423
1.1

Fault-finding table  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . 200423

DIAGNOSTICS

2

©

 200423

Contents

1

ΧΦ65/75/85 series

7

©

 200423

1-1

Steering gear, general

DIAGNOSTICS

ΧΦ65/75/85 series

7

1

1. STEERING GEAR, GENERAL

1.1 FAULT-FINDING TABLE

SYMPTOM: HEAVY STEERING, TO BOTH SIDES

Possible cause

Remedy

Tyre pressure of steerable wheels too low

Check the tyre pressure. Increase tyre pressure to 

the specified value.

Fifth-wheel coupling damaged or insufficiently 

lubricated.

Inspect/lubricate fifth-wheel coupling.

Axle load of steerable axle(s) too high

Check axle load.

Adjust the load.

Steering oil level too low

Check steering oil level.

Top up oil and bleed system.

Check system for leaks.

Air in the system

Bleed the system.

Check steering oil for foaming.

Filter is extremely filthy

Check filter. If necessary, replace the O-ring.

Steering oil line kinked or pinched off

Check routing of the steering oil lines.

The supply opening in the reservoir is (partially) 

blocked.

Check supply opening in the reservoir.

Tight steering shaft bearings or universal joint(s) of 

steering column

Jack up steerable axle(s) and check the steering 

column tightening torque.

Tight swivel axle bearing

Check steerable axle(s).

Excessive caster

Check caster. Reduce if necessary.

System pressure too low

Check maximum system pressure.

Replace pressure-limiting valve or steering pump.

Steering pump output too low

Check pump output.

Check whether the flow control valve is jammed.

If necessary, replace steering pump.

Excessive internal leakage of steering box or slave 

cylinder (if fitted)

Check internal leakage of steering box/slave 

cylinder.

DIAGNOSTICS

1-2

©

 200423

Steering gear, general

1

ΧΦ65/75/85 series

7

SYMPTOM: HEAVY STEERING, TO ONE SIDE

Possible cause

Remedy

Tyre pressure of steerable wheels too low

Check the tyre pressure. Increase tyre pressure to 

the specified value.

Fifth-wheel coupling damaged or insufficiently 

lubricated.

Inspect/lubricate fifth-wheel coupling.

Steering oil level too low

Check steering oil level.

Top up oil and bleed system.

Check system for leaks.

Air in the system

Bleed the system.

Check steering oil for foaming.

Wheel deflection limiting valves incorrectly 

adjusted.

Check setting of the wheel deflection limiting 

valves.

Tight swivel axle bearing

Check steerable axle(s).

Misalignment of the universal joints of the steering 

column

Check/adjust position of the universal joints in 

relation to each other.

Excessive internal leakage of steering box or slave 

cylinder (if present) on one side

Check internal leakage of steering box/slave 

cylinder.

SYMPTOM: HEAVY STEERING, OCCASIONALLY

Possible cause

Remedy

Fifth-wheel coupling damaged or insufficiently 

lubricated

Inspect/lubricate fifth-wheel coupling.

Steering oil level too low

Check steering oil level.

Top up oil and bleed system.

Check system for leaks.

Air in the system

Bleed the system.

Check steering oil for foaming.

The steering oil line is temporarily kinked or 

pinched off

Check routing of the steering oil lines.

Supply opening in the reservoir temporarily 

blocked

Check reservoir for impurities.

Steering pump output too low because flow control 

valve is jammed

Check the flow control valve for smooth operation.

Low steering pump output in "cold condition" and at 

low engine speed because the partitions jam in the 

rotor

Check pump output when steering pump is "cold".

Replace steering pump.

Excessive internal steering box leakage at lower 

pressures

Check internal steering box leakage at a preset 

pressure of 15 - 30 bar.