power steering fluid LAND ROVER DISCOVERY 1995 User Guide

STEERING
1
DESCRIPTION AND OPERATION DESCRIPTION
The power assisted steering system incorporates a
compression joint in the lower shaft, designed to
collapse on impact and for certain countries, an air
bag located in the centre of the steering wheel.
The mis-alignment of the upper steering column with
the steering box and the inclusion of two universal
joints and a compression joint in the lower shaft, is
also designed to prevent frontal impact moving the
column toward the driver.
The steering box is located behind the first cross
member of the chassis and is connected to the road
wheels by the drag link and track rod. An hydraulic
damper absorbs shocks in the steering, caused by
road wheel deflections when operating on rough
terrain.Power steering system
The power steering system comprises a hydraulic
pump which is belt driven from the engine and
supplied with fluid from a reservoir that also acts as a
cooler.
The steering box houses a self neutralizing rotary
valve which is part of the worm/valve assy and a
hydraulic piston/rack to assist the mechanical
operation.
The rotary valve which is operated by movement of
the steering wheel, directs fluid pressure to the
appropriate side of the hydraulic piston/rack to provide
assistance.
Power steering system
1. Hydraulic pump
2. Fluid reservoir
3. Steering box
4. Upper column
5. Universal joints
6. Lower shaft
7. Compression joint
8. Drag link

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 - retension.
See ENGINE, Repair, 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 achieved?
YES - steering box defective
Not at any speed go to 9.
Not at idle go to 7.
7.Is idle speed correct?
YES- Goto8.
NO - Correct idle speed -
If 3.9
See ENGINE TUNING DATA,
Information, Engine 3.9 V8i
If TdiSee ENGINE TUNING DATA,
Information, 300 Tdi Engine
If MpiSee ENGINE TUNING DATA,
Information, Engine - Mpi - 2.0 Litre
8.Is problem resolved?
YES - end
NO - go to 9.
9.Bypass steering box using adaptor tap
LRT-57-001
10.Is correct pressure obtained?
YES - defective steering box
NO - defective steering pump
CAUTION: Do not hold steering wheel on
full lock for more than 30 seconds in any
one minute to avoid overheating fluid and
possibly damaging seals.
NOTE: 1. Excessive pressure in the
system is almost always caused by a
faulty relief valve in the PAS pump.
NOTE: 2. Insufficient pressure in the
system is usually caused by low fluid level
or PAS pump drive belt slip, or one of the
following: PAS system leaks, faulty PAS pump
relief valve, fault in steering box valve and worm
assembly, leak at piston in steering box, worn
components in PAS pump or box.

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. Hose LRT-57-030.
E. Test adaptor LRT-57-001.
F. Pressure gauge LRT-57-005.
G. Thread adaptor LRT-57-004.
H. Thread adaptor LRT-57-022.Procedure
1.A hydraulic pressure gauge and test adaptor is
used to test power steering system. This gauge
is able to measure 140 kgf/cm
2. The maximum
power steering system pressure is 77 kgf/cm2.
2.Some fault conditions of hydraulic pump may
obtain pressures up to 105 kgf/cm
2. Pressure on
gauge is same pressure being exerted upon
steering wheel. When testing, turn steering
wheel gradually while reading pressure gauge.
3.Check and maintain maximum fluid level of
reservoir.
4.Examine power steering units and connections
for leaks. All leaks must be rectified before
attempting to test the system.
5.Check steering pump drive belt tension.
See
ENGINE, Repair, Drive Belt
6.Assemble test equipment and fit to vehicle, as
shown in RR3959M.
7.Open tap of adaptor.
8.Bleed system, take care not to overload
pressure gauge.
9.With system in good condition, pressures should
be:
(A) Steering wheel held on full lock and engine
running at 1,000 rev/min, 70 to 77 kgf/cm
2.
(B) Steering wheel held on full lock and engine
idling, 28 kgf/cm
2.
Checks should be carried out on both full lock
positions.
CAUTION: Do not maintain this pressure
for more than 30 seconds in any one
minute to avoid overheating fluid and
possibly damaging seals.
10.Release steering wheel and with engine idling.
Pressure should read below 7 kgf/cm
2.
11.If pressures differ to those given a fault exists.
12.To determine if fault is steering box or pump.
Close adaptor tap for a maximum five seconds.
13.If gauge does not register specified pressure,
pump is faulty.
14.Fit a new pump, bleed system and repeat test. If
low pressure or a substantial imbalance exists,
fault is in steering box valve and worm
assembly.

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
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 symptomInsufficient
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

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 Owner's 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 in doubt change units in pairs, side
to side.
6.Is problem resolved?
YES - end
NO - continue.
7.Check steering damper.
See Steering Damper
8.Is problem resolved?
YES - end
NO - continue.
9.Check wheel balance
10.Is problem resolved?
YES - end
NO - contact local technical office.POWER STEERING FLUID LEAKS
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Are hoses or joints leaking? Check on full lock
with engine at 2000 rev/min.
YES - loosen and retorque joints.
NO - go to 6.
4.Does leak remain?
YES - change PAS pipe.
NO - end.
5.Does leak remain?
YES - suspect seal in component. Check and
replace as necessary.
NO - end.
6.Is oil escaping from filler cap?
YES - bleed system.
See Repair, Power
Steering System - Bleed
NO - go to 8.
7.Is oil still escaping from filler cap?
YES - go back to 1.
NO - end.
8.Is oil leaking from PAS pump?
YES - go to 10.
NO - continue.
9.Is oil leaking from PAS box?
YES - go to 10.
NO - end.
10.Clean unit, add tracer dye to system. Retest
11.Is oil still leaking?
YES - establish leak point. Repair or replace
unit as necessary.
NO - end.

STEERING
9
FAULT DIAGNOSIS POWER STEERING SYSTEM - EXCESSIVE NOISE
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Is pressure hose from pump to box touching
body in a hard foul condition?
YES - reroute hose away from body.
NO - go to 5.
4.Does noise remain?
YES - continue.
NO - end.
5.Is noise a whistle or hiss on full lock?
YES - noise is not a fault unless excessive.
Compare with other vehicles
NO - go to 8.
6.Is noise excessive?
YES - continue.
NO - end.
7.Change steering box and/or pump.
8.Is noise a squeal on full lock?
YES - check/reset drive belt tension.
See
ENGINE, Repair, Drive Belt
NO - go to 10.
9.Does squeal remain?
YES - drive belt contaminated, change belt.
NO - end.
10.Is noise a continuous moan?
YES - bleed PAS system.
See Repair, Power
Steering System - Bleed
NO - go to 13.
11.Does moan remain?
YES - do figure 8 manoeuvres.
NO - end.
12.Does moan remain?
YES - continue
NO - end.13.Is noise an intermittent "grunt"?
YES -
See Power Steering System - Grunt
NO - continue.
14.Is it a clunking noise?
YES - reset drive belt tension.
See ENGINE,
Repair, Drive Belt
NO - contact local technical office.
15.Does noise remain?
YES - Suspect suspension or drive train.
NO - end.
POWER STEERING SYSTEM - GRUNT
Steering box grunts intermittently when turning
from lock to lock:
1.Is fluid level correct?
YES - go to 3.
NO - refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Does grunt remain?
YES - continue
NO - end.
3.Is correct low pressure hose ANR 3152, steering
box to reservoir fitted?
YES - go to 5.
NO - Fit correct hose.
4.Does grunt remain?
YES - continue
NO - end.
5.Purge box by doing figure 8 manoeuvres e.g. on
car park, followed by 10 minutes normal road
use.
6.Does grunt remain?
YES - Contact local technical office
NO - end.

57STEERING
12
FAULT DIAGNOSIS Steering column alignment
1.Place vehicle on level ground. Measure the
angle of lower steering shaft using a Pernumeter
placed on the shaft between the universal joints.
The angle should measure a minimum of 12Ê.
2.If necessary, realign the shaft. Release the five
fixings securing the steering column. Position
column as required. Tighten the fixings evenly,
27 Nm.
3.Loosen the three screws securing lower steering
column shroud to upper shroud ensure lower
shroud is clipped to upper shroud. Reposition
shroud, tighten screws.
4.Recheck steering column angle.
Steering box adjustment
1.Check steering box adjustment.
See
Adjustment, Power Steering Box
Steering damper check
1.Check condition of steering damper
See
Steering Damper
VISUAL CHECK AND BASIC ADJUSTMENTS
NOTE: It is important that the following
instructions are carried out in the
sequence shown and the results recorded.
1.Road springs - check that road springs are
correctly seated and are to correct specification
for vehicle. For spring specification.
See
GENERAL SPECIFICATION DATA,
Information, Road Springs Data
2.Ride height - measure trim height from wheel
centre to wheelarch eyebrow. Record results on
data sheet.
3.Check/top up power steering fluid
See Repair,
Power Steering Fluid Reservoir
4.Check tension and condition of drive belt.See
ENGINE, Repair, Drive Belt
5.Track rod/drag link - check condition of track rod,
drag link and ball joints.
See Repair, Drag Link
and Drag Link Ends
If either component is damaged, check operation
of steering damper and steering box for
smoothness. Replace all damaged or worn
components that impair the operation of the
steering system.
6.Suspension bushes - examine all steering and
suspension bushes for signs of wear and
deterioration. Also check all fixings for torque
relaxation. Tighten to correct torque value.
See
FRONT SUSPENSION, Specifications, torque,
Torque Values
7.Oil leaks - check front and rear axle hubs for
leak and repair as necessary.
8.Brake system - check brake system for leaks,
pipe condition, pad wear/contamination, disc
wear/condition and ABS sensors for correct
fitting.
9.Hub end float - check movement in the hubs by
rocking the wheels.
10.Check front wheel alignment. Vehicles displaying
a tendency to veer more than considered
allowable, it is permissible to set the front track
to parallel.
11.Having completed all the above checks and
adjustments, road test vehicle.
See Road Test
Procedure
Attempting to reproduce the symptoms
established earlier. If symptoms still exist refer to
relevant Diagnostic Chart.

STEERING
1
REPAIR POWER STEERING FLUID PIPES
Service repair no - 57.15.21
CAUTION: If any joints are disconnected, it
is essential that open pipe and ports are
plugged to prevent ingress of dirt.
The following procedures must be followed when
refitting fluid pipes:
Power steering pump
1.Remove plugs, place clamp on feed hose.
V8i Steering pump illustrated
2.Push hose onto pump.
3.Hold clamp in position, Tighten to
3 Nm.
4.Fit high pressure union into pump.
5.Hold pipe in correct position. Tighten to
20 Nm.
6.Remove plugs and refit pipes to steering box,
leave fingertight.
7.Tighten to torque: 16mm thread
20 Nm.
14mm thread15 Nm.
Power steering reservoir
1.Remove plugs and refit pipes and clamps.
2.Tighten clamps to3 Nm.

57STEERING
2
REPAIR POWER STEERING BOX
Service repair no - 57.10.01
General precautions
1.Whenever any part of system, is removed or
disconnected, utmost cleanliness must be
observed.
2.Disconnected ports and hoses must be plugged
to prevent ingress of dirt. If metal sediment is
found in system, establish cause rectify and
flush system.
3.Do not start engine until reservoir is full as pump
will be damaged.
4.Metric pipe fittings are used with 'O' ring pipe
ends on fittings to steering box.
5.Follow normal 'O' ring replacement procedure
whenever pipes are disconnected.
6.Ensure compatible metric components when
fitting replacement pipes.
CAUTION: Before removing any parts of
steering linkage, it is imperative that road
wheels are positioned straight ahead.
Then steering wheel removed to prevent rotary
coupler being wound up or damaged.
CAUTION: After refitting steering linkage
parts follow correct procedure to ensure
that road wheels, steering box and
steering wheel are correctly positioned relative to
each other when in straight ahead condition. If
steering wheel requires repositioning, ensure that
drive pegs on rotary coupler are correctly
positioned before steering wheel is replaced.
This ensures drive pegs locate in their holes in
rear of steering wheel.
After final alignment connect rotary coupler
multiplug, tighten steering wheel securing nut and
fit air bag - if fitted or steering wheel trim pad.
NOTE: When drag link is disconnected
from steering box, travel available at
steering wheel to each full lock is not
equal.
Remove
1.Site vehicle on level surface.
2.Open bonnet[hood].
3.Remove filler cap from power steering fluid
reservoir.
4.Clean steering box.
5.Disconnect feed and return pipes from steering
box.
6.Plug open pipes and steering box ports to
prevent ingress of dirt.
7.Support chassis front on axle stands. Or raise
vehicle on a hoist.
WARNING: Ensure wheels are chocked,
parking brake is applied, and low range
selected.

57STEERING
4
REPAIR
Refit
15.Position steering box to chassis side member,
ensuring locating peg is engaged. Tighten bolts
to
81 Nm.
16.Fit pinch bolt and nut securing universal joint to
power steering box. Tighten to
25 Nm.
17.Position tie bar, tighten bolts and nut to81 Nm,
starting with tie bar to mounting nut, then
loosen nut and bolts by one complete turn.
18.Check steering box, adjust if necessary.See
Adjustment, Power Steering Box
19.Refit drag link to drop arm tighten nut to40 Nm.
20.Fit undertray.
21.Lower vehicle to ground.
22.Remove plugs and refit pipes to steering box.
Tighten 16mm thread to
20 Nm.
14mm thread to15 Nm.
23.Remove filler cap. Fill reservoir to oil level mark
on dipstick. Use recommended fluid.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended Lubricants and
Fluids
and bleed power steering system.See
Power Steering System - Bleed
24.Recheck fluid level and replace cap.
25.With engine running, test steering system for
leaks by holding steering in both full lock
directions.
CAUTION: Do not maintain this pressure
for more than 30 seconds in any one
minute, to avoid oil overheating and
possible seal damage.
26.Test drive vehicle: using both full lock directions,
to settle steering components. If possible, drive
vehicle over speed bumps and include harsh
braking.
WARNING: Do not test drive vehicle on
public highway.
27.Drive vehicle in a straight line on level ground
and stop.
28.Tighten tie bar to mounting nut to
110 Nm.
29.Tighten bolts securing tie bar to81 Nm.
30.Ensure steering wheel is correctly aligned when
wheels are positioned straight ahead.
31.If necessary reposition steering wheel.
See
Steering Wheel
32.Road test vehicle.