engine LAND ROVER DEFENDER 1996 Workshop Manual

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
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
11
FAULT DIAGNOSIS STIFF STEERING CHECKLIST
NOTE: Having completed visual checks
and steering assessment and confirmed
that vehicle steering load is incorrect carry
out the following procedure in order shown.
Steering wheel 'torque to turn' loads
1.Raise vehicle so both front wheels free.
2.With engine off, centralise steering wheel, and
remove steering wheel decal. Using torque
wrench on column nut, check torque required to
turn the steering wheel one turn in each
direction.
3.Record readings obtained in each direction.
Reading should be
4.40 Nm (3.5 lbf/ft).
NOTE: If figures are in excess of that
specified carry out steering box tie bar
reset below. If figures are as specified
See
Visual Check and Basic Adjustments
.
Steering box tie bar reset
1.Loosen the tie bar fixings one complete turn.
2.Drive vehicle carefully a short distance (within
the dealership) applying full lock in both
directions in order to settle steering components.
Drive vehicle over speed bumps and include
harsh braking if possible.
WARNING: Do not drive on public
highway.
3.Near end of operation 2. ensure vehicle is driven
in a straight line on level ground and halted.
4.Tighten panhard rod mounting arm nut to
110
Nm (81 lbf/ft).
5.Tighten the 2 fixings, tie bar to steering box, to
81 Nm (60 lbf/ft).
6.Recheck steering wheel torque to turn. If torque
reading is still greater than specified, carry out
steering shaft universal joint lubrication.Lower steering shaft universal joint lubrication
1.Check lower steering shaft is correctly phased
See Repair, Lower Steering Shaft and
Universal Joints
.
2.Lubricate universal joints with an anti-seizure
type penetrating spray. Work the joints to ensure
full penetration of the spray by driving vehicle
and steering from lock to lock.
3.If steering stiffness still persists carry out swivel
pin preload setting.
Swivel pin preload setting
1.The swivel pin preload setting must be checked
and set
See FRONT AXLE AND FINAL DRIVE,
Overhaul, Front Stub Axle, Constant Velocity
Joint and Swivel Pin Housing
.
Note that a pull load of 1.16 - 1.46 kg is required
after the axle shaft and swivel housing seal have
been removed.
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
.

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
.

STEERING
7
REPAIR POWER STEERING PUMP
Service repair no - 57.20.14
Remove
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
.
1.Disconnect battery.
2.Remove viscous fan unit
See COOLING
SYSTEM, Repair, Viscous coupling and fan
.
3.Restrain steering pump pulley, slacken but do
not remove 3 bolts securing pulley.
4.Remove drive belt
See ELECTRICAL, Repair,
Auxiliary drive belt
.
5.Remove bolts and remove pulley.
6.Position suitable container beneath steering
pump.
7.Slacken retaining clip and disconnect return
hose from steering pump.
8.Disconnect high pressure pipe from steering
pump.
9.Allow steering fluid to drain into container.
CAUTION: Plug all connections to prevent
ingress of dirt.
10.Remove 4 bolts securing steering pump bracket
to engine auxiliary mounting bracket.
11.Remove pump and bracket assembly.
12.Remove 3 bolts and detach mounting bracket
from pump.
Refit
13.Fit mounting bracket to replacement steering
pump. Tighten bolts to
9 Nm (7 lbf/ft).
14.Fit pump and bracket to auxiliary mounting
bracket. Tighten bolts to
35 Nm (26 lbf/ft).
15.Connect high pressure feed pipe to steering
pump and tighten to
20 Nm (15 lbf/ft).
16.Connect return hose to steering pump. Tighten
retaining clip to
3 Nm (2 lbf/ft).
17.Position pulley to steering pump, coat threads of
bolts with Loctite 242; fit but do not fully tighten
bolts.
18.Fit drive belt
See ELECTRICAL, Repair,
Auxiliary drive belt
.
19.Restrain steering pump pulley, tighten bolts to
10
Nm (7lbf/ft).
20.Fit viscous fan unitSee COOLING SYSTEM,
Repair, Viscous coupling and fan
.
21.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 ELECTRICAL, Repair, Auxiliary
drive belt
.

70BRAKES
2
DESCRIPTION AND OPERATION REV: 05/99 OPERATION
Master cylinder
A tandem master cylinder, which is assisted by a light
weight, short, compact servo, is fed by a divided fluid
reservoir. The rear section supplies fluid for the
primary circuit and the front section the secondary
circuit.
When the brakes are off, the fluid can move
unrestricted between the dual line system and the
separate reservoirs in the fluid supply tank.
When the footbrake is applied, the primary plunger
assembly moves up the cylinder bore and the
pressure created acts in conjunction with the primary
spring to overcome the secondary springs, thus
moving the secondary plunger assembly up the bore.
At the same time initial movement of both plungers
takes the recuperating seals past the cut-off holes in
the cylinder chambers 'A' and 'C',see J6321, and
applies pressure to the fliud in those chambers, which
is directed to the respective circuits.
The fluid in chambers 'B' and 'D'is unaffected by
movement of the plungers and can move unrestricted
between the separate chambers and respective
reservoirs in the fluid supply tank, both before and
during brake application. When the brakes are
released, the plunger assemblies, aided by the return
springs are retracted faster than the fluid; this creates
a depression between the fluid in chambers 'A' and
'C'and the recuperation seals.
The recuperation seals momentarily collapse allowing
fluid in chambers 'B' and 'D'to flow through the holes
in the plungers, over the collapsed seals and into
chambers 'A' and 'C'respectively. The movement of
fluid from one set of chambers to the other, is
compensated for by fluid from the separate reservoirs
in the supply tank moving through the feed holes in
the cylinder. Conversely, the final return movement of
the plunger assemblies causes the extra fluid in
chambers 'A' and 'C'to move through the cut off holes
into the fluid reservoir.The servo unit provides controlled power assistance
to to the brake pedal when pressure is applied. Power
is obtained from a vacuum pump located on the RH
side of the engine cylinder block. The vacuum is
applied to both sides of a flexing diaphragm, and by
admitting atmosheric pressure to the rear diaphragm,
assistance is obtained. The servo unit is mounted
between the brake pedal and master cylinder and is
linked to these by push rods. Should a vacuum failure
occur, the two push rods will act as a single rod
allowing the brakes to function in the normal way,
although more effort will be required to operate the
brake pedal.
Hydraulic system
A brake fluid loss switch is fitted to the master cylinder
reservoir filler cap. The switch is wired to a warning
light on the vehicle fascia and will illuminate as a bulb
check when the ignition is switched on and
extinguishes when the engine is running and the
handbrake is released. A hydraulic failure in the
system will result in fluid loss, causing the warning
light to illuminate.
On 90 models a pressure reducing valve (PRV), fitted
to the RH bulkhead in the engine compartment,
maintains the braking balance, see J6322. Pressure
to the rear calipers is regulated by the PRV, this valve
is of the failure by-pass type, allowing full system
pressure to the rear brake calipers in the event of a
front (secondary) circuit failure.
NOTE: In some countries, a pressure
reducing valve may be fitted to 110 models
to conform to legal requirements.

BRAKES
1
REPAIR GENERAL BRAKE SERVICE PRACTICE
Brake fluid precautions
WARNING: Do not allow brake fluid to
come into contact with eyes or skin.
CAUTION: Brake fluid can damage
paintwork, if spilled wash off immediately
with plenty of clean water.
CAUTION: Use only correct grade of brake
fluid. If an assembly fluid is required use
ONLY brake fluid. Do NOT use mineral oil,
i.e. engine oil etc.
CAUTION: Thoroughly clean all brake
calipers, pipes and fittings before
commencing work on any part of the brake
system. Failure to do so could cause foreign
matter to enter the system and cause damage to
seals and pistons which will seriously impair the
efficiency of the brake system. To ensure the
brake system efficiency is not impaired the
following warnings must be adhered to :-
·DO NOT use any petroleum based cleaning
fluids or any proprietary fluids containing
petrol.
·DO NOT use brake fluid previously bled from
the system.
·DO NOT flush the brake system with any fluid
other than the recommended brake fluid.
The brake system should be drained and flushed
at the recommended service intervals.
Cover all electrical terminals carefully to make
absolutely certain that no fluid enters the
terminals and plugs.FLUID LEVEL CHECK/TOP UP
WARNING: Clean reservoir body and filler
cap before removing cap. Use only fluid
from a sealed container.
1.Park vehicle on level ground.
2.Check level is between 'MIN' and 'MAX' marks.
3.If level is below 'MIN' mark top up fluid level to
'MAX' mark on reservoir, using correct fluid.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended lubricants and
fluids
CAUTION: Do not fill reservoir above
maximum line.