belt LAND ROVER DISCOVERY 1995 Repair Manual

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
7
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 as illustrated in
RR3568M the rotary valve in the steering box acts as
a pressure relief valve, allowing fluid A to flow freely
through the steering box and back to the reservoir and
pump inlet B.
No demand for assistance
1. Reservoir
2. Pump
3. Pressure control ball valve and spring
4. Flow control valve and spring
5. Press fit plug (ball bearing)
6. Restrictor
The ball plug item 5 is pressed into the valve 4
during manufacture and determines the opening
pressure of pressure relief valve 3.No flow, through box - High pressure
When the steering is turned, the rotary valve
effectively stops all fluid flow through the steering box,
thus causing an increase in pressure A. This increase
in pressure is felt in the flow control valve spring
chamber where, at a pre-determined pressure the
relief valve 3 will open and allow the pressure to
escape. The fall in pressure in the flow control spring
chamber, allows the flow control valve to move to the
right, which in turn allows pump output A to escape
directly into the pump inlet B, as seen in RR3569M.Assistance demanded
As soon as the steering wheel is released after
making a turn, the system reverts to the condition
seen in RR3568M and the road wheels are returned
to the straight ahead position by the mechanical
steering geometry.
In the event of any hydraulic failure steering control
though heavy, will be maintained through the
mechanical components in the steering box.

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.

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
3
ADJUSTMENT FRONT WHEEL ALIGNMENT
Service repair no - 57.65.01
Checking Toe-out dimensions
NOTE: No Adjustment is provided for
castor, camber or swivel pin inclinations.
1.Set vehicle on level ground with road wheels
positioned straight ahead.
2.Push vehicle back and forwards to settle linkage.
3.Measure toe-out at horizontal centre-line of
wheels.
4.Check tightness of clamp bolt fixings. Tighten to
14 Nm.
Adjust
5.Loosen adjuster sleeve clamp.
6.Rotate adjuster to lengthen or shorten track rod.
7.Check toe-out setting as instructions 1 to 4.
When toe-out is correct, tap steering linkage ball
joint, in directions of arrows shown, to maximum
of their travel. This ensures full unrestricted
working travel.
8.Tighten clamp bolts to
14 Nm.
POWER STEERING PUMP DRIVE BELT
Service repair no - 57.20.01
Adjust
NOTE: For details of drive belt adjust
procedure
See ENGINE, Repair, Drive
Belt

57STEERING
6
REPAIR Refit
6.Position reservoir, connect feed and return
hoses and tighten clamps to
3 Nm.
7.Fit reservoir in clamp, tighten clamp bolt.
8.Fill reservoir to 'MAX' mark on dipstick with
power steering fluid.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids
9.Fit undertray.
10.Bleed power steering system.
See Power
Steering System - Bleed
POWER STEERING PUMP DRIVE BELT
Service repair no - 57.20.02
NOTE: For details of drive belt remove and
refit.
See ENGINE, Repair, Drive Belt
POWER STEERING PUMP - V8i
Service repair no - 57.20.14
NOTE: The power steering pump is not
serviceable. Fit new pump if worn or
damaged.
Remove
1.Disconnect battery negative lead.
2.Remove drive belt from steering pump.
See
ENGINE, Repair, Drive Belt
3.Remove undertray.
4.Remove fan blades and viscous coupling.
See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
5.Position drain tin beneath steering pump.
6.Using a 9 mm Allen key to restrain steering
pump pulley, remove 3 bolts securing pulley to
pump; remove pulley.

STEERING
7
REPAIR 7.Loosen clamp securing reservoir hose to
steering pump; disconnect hose.
8.Disconnect high pressure pipe from steering
pump.
CAUTION: Plug the connections.
9.Release ht lead from clip
10.Remove 3 bolts securing steering pump.
Remove pump and recover engine lifting
bracket.
NOTE:Do not carry out further
dismantling if component is removed for
access only.
11.Remove 5 bolts securing front mounting plate.
12.Fit front mounting plate to replacement steering
pump. Tighten bolts to
9 Nm.
Refit
13.Position steering pump and engine lifting plate,
fit bolts. Tighten to
35 Nm.Secure ht lead in
clip.
14.Connect high pressure pipe to steering pump,
tighten union to
20 Nm.
15.Connect reservoir hose to steering pump.
Tighten clamp to
3 Nm.
16.Position pulley to pump, coat threads of bolts
with Loctite 242.
17.Restrain pulley using a 9 mm Allen key, fit bolts.
Tighten to
10 Nm.
18.Fit drive belt.See ENGINE, Repair, Drive Belt
19.Fit fan blades and viscous coupling.See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
20.Fit undertray.
21.Reconnect battery negative lead.
22.Bleed power steering system.
See Power
Steering System - Bleed
POWER STEERING PUMP - Tdi
Service repair no - 57.20.14
Remove
1.Remove fan blades and viscous coupling.
See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
2.Restrain steering pump pulley, loosen but do not
remove 3 bolts securing pulley.
3.Remove drive belt.
See ENGINE, Repair,
Drive Belt
4.Remove 3 bolts securing steering pump pulley,
remove pulley.
5.Remove undertray.
6.Position drain tin beneath steering pump.

57STEERING
8
REPAIR 7.Loosen clamp securing reservoir hose to
steering pump, disconnect hose.
8.Disconnect high pressure pipe from steering
pump.
CAUTION: Plug the connections.
9.Remove 4 bolts securing steering pump to
mounting bracket, remove pump.
NOTE:Do not carry out further
dismantling if component is removed for
access only.
10.Remove 3 bolts securing mounting plate to
pump, remove plate.
11.Fit mounting plate to replacement steering
pump. Tighten bolts to
9 Nm.
Refit
12.Position steering pump, fit 3 bolts. Tighten to
35
Nm.
13.Connect high pressure pipe to steering pump.
Tighten to
20 Nm.
14.Connect reservoir hose to steering pump.
Tighten clamp to
3 Nm.
15.Position pulley to steering pump, coat threads of
bolts with Loctite 242; fit but do not fully tighten 3
bolts.
16.Fit drive belt.
See ENGINE, Repair, Drive Belt
17.Restrain steering pump pulley, tighten bolts to10
Nm.
18.Fit fan blades and viscous coupling.See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
19.Fit undertray.
20.Bleed power steering system.
See Power
Steering System - Bleed