300Tdi Discovery
57
STEERING
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
Box
NO -
See Overhaul, Power Steering Box
Symptom:-
Insufficient power assistance - castor return
action normal.
1. Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Continue.
2. Is fluid level correct?
NO -
Check fluid level
See Repair, Power
Steering Fluid Reservoir
YES - Check system for air locks.
See Repair,
Power Steering System - Bleed
3. Is pressure correct?
NO -
Check fluid pressure.
See Power
Steering System - Test
If pressure is not correct after bleeding
the system, renew pump.
See Repair,
Power Steering Pump
YES -
See Overhaul, Power Steering Box
Symptom:-
Steering heavy - stiff, poor castor return action.
1. Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Check universal joints for seizure and
correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
Check power steering box adjustments.
See Overhaul, Power Steering Box
2. Is the power assistance satisfactory?
NO -
See fault symptom Insufficient
assistance, (castor return action
normal).
YES - Disconnect drag link from drop arm and
check steering column and box for
stiffness.
See Repair, Drag Link and
Drag Link Ends
3. Is the steering stiff with the drag link
disconnected?
NO -
Check steering ball joints for seizure and
axle swivels lubrication and resistance.
See Repair, Drag Link and Drag Link
Ends See FRONT AXLE AND FINAL
DRIVE, Overhaul, Front Stub Axle,
Constant Velocity Joint and Swivel Pin
Housing Non ABS See FRONT AXLE
AND FINAL DRIVE, Overhaul, Front
Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS
YES - Disconnect the lower steering shaft and
check the column and box for stiffness.
See Repair, Lower Steering Shaft and
Universal Joints
4. Is the steering column stiff to turn when
disconnected from the box?
NO -
Remove and overhaul box.
See
Overhaul, Power Steering Box
YES - Adjust steering column.
See Stiff
Steering Checklist
