Land Rover Defender 300tdi Workshop 3rd Edition Rover Manual

57STEERING
4
DESCRIPTION AND OPERATION Rotary valve misaligned
Demand for assistance (Valve misaligned)
When the steering wheel and input shaft is turned,
steering resistance transmitted to the worm causes
the torsion bar to be twisted and the valve ports to be
misaligned for a right or left turn. The misalignment of
the valve ports directs all fluid pressure A to one side
of the piston only and allows displaced fluid B on the
other side.
When demanding maximum assistance, any
excessive fluid output from...

STEERING
5
DESCRIPTION AND OPERATION Pump and regulator valve operation
The pump which is belt driven from the engine is an
eccentric roller type and also houses the pressure
regulator and flow control valve. The pressure is
controlled by a spring loaded ball valve (3) which is
housed inside the flow control valve piston (4).
No demand for assistance High flow through box -
Low pressure
With no demand for assistance the rotary valve in the
steering box acts as a pressure relief valve, allowing
fluid (A)...

STEERING
1
FAULT DIAGNOSIS INSUFFICIENT POWER ASSISTANCE
1.Is fluid level correct?
YES - go to 3.
NO - Fill/bleed sytem
2.Is problem a leak?
YES - Diagnose
See Power Steering Fluid
Leaks
.
NO - continue
3.Is drive belt tension correct?
YES - go to 5.
NO - Is drive belt worn or contaminated with oil?
See ELECTRICAL, Repair, Auxiliary drive
belt
.
4.Is problem resolved?
YES - end
NO - continue
5.Carry out pressure test at idle and 1000 rev/min.
See Power Steering System - Test.
6.Is correct pressure...

57STEERING
2
FAULT DIAGNOSIS POWER STEERING SYSTEM - TEST
NOTE: If steering lacks power assistance.
Check pressure of hydraulic pump before
fitting new components. Use fault
diagnosis chart to assist in tracing faults.
A. Steering box.
B. Steering pump.
C. Existing hose, steering box to pump.
D. HoseLRT-57-030.
E. Test adaptorLRT-57-001.
F. Pressure gaugeLRT-57-005.
G. Thread adaptorLRT-57-004.
H. Thread adaptorLRT-57-022.Procedure
1.A hydraulic pressure gauge and test adaptor is
used to test power...

STEERING
3
FAULT DIAGNOSIS STEERING DAMPER
The power steering system, as well as reducing the
effort required to manoeuvre the vehicle when
parking, also helps to dampen any deflections of the
road wheels, being transmitted back to the steering
wheel.
When operating the vehicle off road, the road wheels
are often deflected by ruts and boulders causing the
steering wheel to turn left and right. This phenomenon
is known as steering kickback. To subdue the effects
of steering kickback, a hydraulic damper is...

57STEERING
4
FAULT DIAGNOSIS Symptom:-
Fluid leaks from steering box seals.
CAUTION: The steering wheel must not be
held on full lock for more than 30 seconds
in one minute, as this may overheat the
fluid and cause damage to the oil seals.
1.Check fluid level
See Repair, Power Steering
Fluid Reservoir
.
Check fluid pressure
See Power Steering
System - Test
.
2.Is pressure high?
YES - Renew pump
See Repair, Power
steering Pump
.
If oil seal leaks persist after renewing the pump
See Overhaul, Power...

STEERING
5
FAULT DIAGNOSIS REV: 05/99 Symptom :-
Steering excessively light/sensitive. Excessive
freeplay at steering wheel.
1.Are steering box adjustments correct?
NO -
See Adjustment, Power Steering Box.
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is within warranty, it must be
returned to manufacturer. No attempt must be
made to introduce backlash.
YES - Suspect worn panhard rod or radius arm
bushes. Check condition of ball joints and the
lower steering...

57STEERING
6
FAULT DIAGNOSIS STEERING STABILITY AND VEER UNDER
BRAKING
Possible cause:
Incorrectly set, swivel pin bearing preload.
Remedy.
1.Follow instructions to overhaul front stub axle,
constant velocity joint and swivel pin
See
FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing
.1. GENERAL STEERING
1.Carry out visual and safety checks
See Visual
and Safety Checks
.
2.Road test vehicle
See Road Test Procedure.
3.Is problem resolved?
YES - end
NO -...

STEERING
7
FAULT DIAGNOSIS 2. STEERING VEER
From 1. GENERAL STEERING:
1.Vehicle veers, not under braking, swap front
tyres side to side.
2.Is problem resolved?
YES - end
NO - continue.
3.Does vehicle now veer in other direction?
YES - fit new tyres
NO - continue.
4.Recentralise steering box
See Adjustment,
Centralise Steering Box.
5.Is problem resolved?
YES - end
NO - contact local technical office.3. VEER UNDER BRAKING
From 1. GENERAL STEERING:
1.Vehicle veers under braking, bleed brake
system.
2.Is...

57STEERING
8
FAULT DIAGNOSIS 4. DIRECTIONAL STABILITY
From 1. GENERAL STEERING:
1.Is directional stability concern when vehicle is
towing?
YES - Check towing/vehicle loading parameters
in Owners Handbook.
NO - go to 3.
2.Is problem resolved?
YES - end
NO - continue.
3.Check condition of rear trailing link/chassis
bushes.
4.Is problem resolved?
YES - end
NO - continue.
5.Check condition of front and rear shock
absorbers. If necessary, change units in pairs,
side to side.
6.Is problem resolved?
YES - end...