power steering fluid LAND ROVER DEFENDER 1996 User Guide

STEERING
1
DESCRIPTION AND OPERATION DESCRIPTION
The steering system incorporates a compression joint
in the lower shaft and is designed to collapse on
impact. The mis-alignment of the upper steering
column with the steering box and the inclusion of two
universal joints, is also designed to prevent the
column moving toward the driver under frontal impact.
The steering box is located behind the first chassis
cross member and is connected to the road wheel
swivel housing by a drag link and track rod. A
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 an
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 column5.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 - 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 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 -
See ENGINE TUNING
DATA, Information, 300 Tdi Engine
.
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. 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 system. This gauge
is able to measure 140 kgf/cm
2. The maximum
power steering system pressure is 77 kgf/cm2.
2.Under certain fault conditions of the hydraulic
pump it is possible to obtain pressures up to 105
kgf/cm
2. It is important to realise that 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 and
renew belt if necessary,
See ELECTRICAL,
Repair, Auxiliary 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 INTRODUCTION, 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
.
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 necessary, 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 - route 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 drive belt tension and remove belt if
necessary
See ELECTRICAL, Repair,
Auxiliary 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 - check drive belt tension and renew belt if
necessary
See ELECTRICAL, Repair,
Auxiliary 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, 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 DIAGNOSISREV: 05/99 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 Spring 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
ELECTRICAL, Repair, Auxiliary 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.
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
.
Attempt to reproduce the symptoms established
earlier. If symptoms still exist refer to relevant
Diagnostic Chart.
STEERING LINKAGE INSPECT
NOTE: When inspecting steering linkages
and ball joints for wear the following items
must be checked.
Steering ball joints
1.Check ball joint rubber boots for security, signs
of cracking or deterioration.
2.Check ball joint assemblies for seizure i.e. no
movement on ball joint and associated
assemblies.
3.Check for excessive wear. This will be evident
as extreme movement on track rod and steering
linkages. Renew parts as necessary
See
Repair, Track Rod and Linkage
,See Repair,
Drag Link and Drag Link Ends
.
Steering linkages
1.Check all linkages for wear, deterioration and
damage. Renew parts as necessary
See
Repair, Track Rod and Linkage
,See Repair,
Drag Link and Drag Link Ends
.

57STEERING
4
REPAIR POWER STEERING BOX
Service repair no - 57.10.01
NOTE: A chassis undertray may be fitted
on some vehicle derivatives to conform to
legal requirements. When under chassis
remove and refit procedures are required, it may
be necessary to remove the undertray
See
CHASSIS AND BODY, Repair, Front undertray
.
General precautions
·Whenever any part of system, is removed or
disconnected, utmost cleanliness must be
observed.
·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.
·Do not start engine until reservoir is full as
pump will be damaged.
·Metric pipe fittings are used with 'O' ring pipe
ends on fittings to steering box.
·Follow normal 'O' ring replacement procedure
whenever pipes are disconnected.
·Ensure compatible metric components when
fitting replacement pipes.
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.
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.Apply park brake, chock rear wheels, raise
vehicle and locate axle stands. Alternatively,
raise vehicle on a hoist.
3.Remove road wheel.
4.Remove panhard rod
See FRONT
SUSPENSION, Repair, Panhard rod
.
5.Disconnect steering damper from drag link.
6.Disconnect drag link from drop arm, see J6305
on opposite page, using a suitable extractor.
7.Slacken, but do not remove nut securing tie bar
to mounting arm.8.Remove 2 bolts securing tie bar to steering box
and move aside.
9.Remove filler cap from power steering fluid
reservoir.
10.Position suitable container under steering box.
11.Disconnect feed and return pipes from steering
box and drain fluid.
12.Plug open pipes and steering box ports to
prevent ingress of dirt. Refit fluid reservoir filler
cap.
13.Centralise steering
See Centralise steering
box
.
14.Remove pinch bolt securing lower shaft
universal joint to power steering box.
15.Remove 4 bolts and 2 tab washers securing
steering box to chassis side member.
16.Withdraw steering box.
17.Clean all mounting faces, unions etc. prior to
refitting.
Refit
18.Position steering box to chassis side member,
ensuring locating peg is engaged. Fit tab
washers and tighten bolts to
81 Nm (60 lbf/ft).
19.Fit pinch bolt and nut securing universal joint to
power steering box spline. Tighten to
25 Nm (18
lbf/ft).
20.Secure tie bar to mounting arm and steering box.
Tighten fixings to
81 Nm (60 lbf/ft),starting with
tie bar to mounting nut, then loosen fixings by
one complete turn.
21.Check steering box and adjust if necessary
See
Adjustment, Power steering box - adjust
.
22.Refit drag link to drop arm and tighten nut to
40
Nm (30 lbf/ft).
Fit new split pin to retaining nut.

STEERING
5
REPAIR REV: 05/99
23.Fit panhard rodSee FRONT SUSPENSION,
Repair, Panhard rod
.
24.Fit road wheels. Lower vehicle to ground and
tighten wheel nuts to correct torque:
Alloy wheels - 130 Nm (96 lbf/ft)
Steel wheels - 100 Nm (80 lbf/ft)
Heavy duty wheels - 170 Nm (125 lbf/ft)
25.Remove plugs and refit feed and return pipes to
steering box. Tighten 16mm thread to
20 Nm (15
lbf/ft),
14mm thread to15 Nm (11 lbf/ft).
26.Remove filler cap. Fill reservoir to oil level mark
on dipstick, using recommended fluid
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended lubricants and
fluids
.
27.Bleed power steering system
See Power
steering system - bleed
.
28.Recheck fluid level and replace cap.
29.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.
30.Test drive vehicle: using both full lock directions,
to settle steering components. If possible, drive
vehicle over uneven ground and include harsh
braking.
WARNING: Do not test drive vehicle on
public highway.
31.Drive vehicle in a straight line on level ground
and stop.
32.Tighten tie bar to mounting nut to
110 Nm (81
lbf/ft).
33.Tighten tie bar to steering box fixings to81 Nm
(60 lbf/ft).
34.Ensure steering wheel is correctly aligned when
wheels are positioned straight ahead.
35.If necessary, reposition steering wheel
See
Steering wheel
.
36.Road test vehicle.

57STEERING
6
REPAIR POWER STEERING SYSTEM - BLEED
Service repair no - 57.15.02
1.Check that fluid level is at maximum level
See
MAINTENANCE , Under bonnet maintenance.
2.Run engine to normal operating temperature.
3.Recheck reservoir fluid level, top up if necessary
NOTE: During operations 4 to 6, maintain
maximum fluid level in reservoir. Do not
increase engine speed or move steering
wheel.
4.With engine at idle speed, slacken bleed screw.
When fluid seeps past bleed screw retighten
screw.
5.Check fluid level.
6.Clean away fluid around bleed screw.
7.Check hose connections, pump and steering box
for fluid leaks by holding steering on full lock in
both directions.
CAUTION: Do not maintain this pressure
for more than 30 seconds in any one
minute to avoid overheating fluid and
possibly damaging seals.
8.Carry out road test.POWER STEERING FLUID RESERVOIR
Service repair no - 57.15.08
Remove
1.Position drain tin beneath reservoir.
2.Slacken mounting bracket clamp bolt and raise
reservoir to gain access to feed and return hose
retaining clips.
3.Slacken clips, disconnect hoses from reservoir,
allow fluid to drain.
4.Remove reservoir.
CAUTION: Plug connections to prevent
ingress of dirt.
CAUTION: Discard fluid drained from
system. Do not allow fluid to contact
paintwork, if spilled, remove fluid and
clean area with warm water.
Refit
5.Position reservoir, connect feed and return
hoses and tighten clips to
3 Nm (2 lbf/ft).
6.Fit reservoir in clamp, tighten clamp bolt.
7.Fill reservoir between upper mark and end of
dipstick with power steering fluid
See
MAINTENANCE , Under bonnet maintenance
.
8.Bleed power steering system
See Power
steering system - bleed
.