1995 LAND ROVER DISCOVERY warning

STEERING
19
REPAIR DRAG LINK AND DRAG LINK ENDS
Service repair no - 57.55.17
Remove drag link
1.Check front wheel alignment.
See Adjustment,
Front Wheel Alignment
2.Ensure wheels are positioned straight ahead
during following procedure.
3.Place vehicle on a hoist, or support front axle on
axle stands.
4.Remove right front road wheel.
5.Disconnect drag link ball joint at swivel housing
arm, using extractor LRT-57-018.
6.Disconnect drag link ball joint at drop arm using
LRT-57-018.
7.Remove drag link.
Remove drag link ends
8.Loosen clamp bolts.
9.Unscrew ball joints.
10.Clean internal threads in drag link.Refit drag link ends
11.Fit replacement ends. Loosely fit clamp bolts.
12.Set ball joints to drag link distance to 28.5mm as
shown.
13.Adjust ball pin centres to nominal length of
924.0mm. this length is adjusted during refit.
14.Centralise steering box.
See Adjustment,
Centralise Steering Box
15.Align steering wheel, if necessary.See
Steering Wheel
Refit drag link
CAUTION: Fit new drag link if existing drag
link is damaged or bent. No attempt
should be made to repair it.
16.Fit drag link. Tighten ball-joint nuts to
40 Nm.
17.Check steering lock stops.See Adjustment,
Steering Lock Stops
18.Ensure full steering travel is obtained between
lock stops. Adjust drag link length to suit.
19.Tap ball joints in direction shown, so both pins
are in same angular plane.
20.Tighten clamp bolts to
14 Nm.
21.Reverse removal procedure. 3 and 4.
22.Road test vehicle.
23.If driving straight ahead and steering wheel is
offset by 0°to±5°in either direction. Remedy by
adjusting drag link length.
WARNING: To correct steering wheel
deviations greater than±5°. Remove and
reposition steering wheel.
See Steering
Wheel

STEERING
1
OVERHAUL POWER STEERING BOX
Service repair no - 57.10.07
Overhaul
NOTE: Overhaul of steering box should
not be carried out during the warranty
period.
WARNING: Wear safety glasses while
removing and refitting circlips and
retaining ring.
CAUTION: Absolute cleanliness is
essential when overhauling power steering
box.
1.Remove steering box from vehicle.See Repair,
Power Steering Box
Remove drop arm using extractor LRT-57-012.
Loosen drop arm securing nut, but do not
remove before using extractor. Remove dirt
excluder from output shaft.
2.Drain oil, remove blanking plugs and bleed
screw. Hold steering box over suitable container,
turn input shaft from lock to lock, until oil is
drained. Refit bleed screw.
3.Rotate retainer ring until one end is 12 mm from
extractor hole. Using a drift through hole in
cylinder, lift retaining ring from groove in cylinder
bore.
4.Remove retainer ring, using a screwdriver.
5.Turn input shaft (left lock on left hand drive, right
lock on right hand drive) until piston pushes out
cover. Turn input shaft fully in opposite direction,
applying pressure to piston.
6.Remove set screw retaining rack pad adjuster.
7.Remove rack adjuster and pad.
8.Remove sector shaft adjuster locknut.
9.Remove four bolts from sector shaft cover.
10.Screw in sector shaft adjuster until cover is
removed.
NOTE: Sealant is applied to hexagon
socket to 'tamperproof' sector shaft
adjuster
11.Slide out sector shaft.

FRONT SUSPENSION
1
REPAIR SELF LOCKING NUTS
WARNING: Where self locking nuts are
removed, they must be replaced with new
nuts of same specification.
PANHARD ROD
Service repair no - 60.10.07.
Remove
1.Remove fixings at mounting arm.
2.Remove fixings at axle bracket.
3.Remove Panhard rod.
4.Press out flexible bushes. Ensure the steel
tubing locates on the outer edge of the bush and
not on the rubber inner.
Refit
5.Fit replacement bushes.
CAUTION: Apply pressure to outer edge of
bush, and not rubber inner.
6.Reverse removal procedure. 1 to 4. Tighten to
88Nm
RADIUS ARM
Service repair no - 60.10.16.
Remove
1.Loosen road wheel retaining nuts.
2.Raise front of vehicle. Support chassis on stands
and remove wheel.
3.Support front axle weight with jack.
4.Remove radius arm to chassis side member
fixings.
5.Disconnect track rod at ball joint.
6.Remove fixings, radius arm to axle.
7.Lower radius arm front end to clear axle and
remove from vehicle.

BRAKES
1
DESCRIPTION AND OPERATION BRAKES
Discovery vehicles have servo assisted brake
systems and the option of an anti-lock brake system.
Information in this section refers to components
relevant to both brake systems. Where the system
components are different they are referred to as ABS
or NON ABS
BRAKE SYSTEM NON ABS
Description
The servo assisted hydraulic braking system is the
dual line type, incorporating primary and secondary
hydraulic circuits.
NOTE: References made to primary or
secondary do not imply main service
brakes or emergency brakes but denote
hydraulic line identification.
The brake pedal is connected to a vacuum assisted
mechanical servo which in turn operates a tandem
master cylinder. The front disc brake calipers each
house four pistons, these pistons are fed by the
secondary hydraulic circuit. The rear disc brake
calipers each house two pistons, these are fed by the
primary hydraulic circuit via a pressure reducing valve.
A brake fluid level switch is incorporated into the
reservoir cap assembly, the switch will immediately
illuminate a warning light in the instrument binnacle
indicating low fluid or sudden fluid loss.
The brake fluid reservoir is divided, the section closest
to the servo feeds the primary circuit and the section
furthest from the servo feeds the secondary circuit.
Under normal operating conditions both the primary
and secondary circuits operate simultaneously on
brake pedal application. In the event of a failure in the
primary circuit the secondary circuit will still function. If
the secondary circuit fails the primary circuit will still
function. The brake pedal travel will be longer in the
event of a half system failure.If the servo should fail, both hydraulic circuits will still
function but would require greater pedal effort due to
the lack of vacuum assistance. The hand operated
parking brake acts on a brake drum at the rear of the
transfer gearbox and is completely independent of the
hydraulic circuits.
Hydraulic circuit non ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve

BRAKES
3
DESCRIPTION AND OPERATION Description of components
1. ABS Modulator unit
To provide the ABS function a Modulator is positioned
within the system between the master cylinder and the
calipers. On both LHD and RHD vehicles it is sited on
the left inner wing [fender]. The Modulator has 8
solenoid valves, 2 for each wheel, 2 expanders and a
recirculation pump. It is non serviceable.
2. Servo/master cylinder
Actuation of the system is provided by a combined
master cylinder and servo assembly attached to the
pedal box, this provides pressure to opposed piston
calipers at each brake pad Twin piston at the front
axle, single piston at the rear.
3. Pressure reducing valve
To maintain the braking balance, pressure to the rear
axle is regulated by a Pressure Reducing Valve (PRV)
This PRV is of the failure bypass type, allowing full
system pressure to the rear axle in the event of a front
circuit failure. It is sited on the left inner wing [fender].
4. Electronic control unit - ECU
ABS control is provided by an electronic control unit
which is positioned on the passenger side of the
vehicle behind the dash panel/glove box.
The ECU, which is non-serviceable, is connected to
the ABS harness by a 35 way connector. non
serviceable.
The ECU continually monitors the brake system,
providing diagnostics in the event of a system
malfunction. Details of how to access the ECU
diagnostics are provided in the Electrical
Troubleshooting Manual.
5.& 6. Front and rear sensors/exciter rings - 4 off
A sensor is sited at each wheel, sensing a 60 tooth
exciter ring. When vehicle is in motion inductive
sensors send signals to ECU. Front exciter ring is
fitted to outside diameter of constant velocity joint
inside each front hub assembly. The rear exciter ring
is bolted to the rear of each brake disc bell.7. Diagnostic plug connection
A diagnostic plug is located behind the dash. To the
left of the steering column on LHD vehicles. To the
right of the steering column on RHD vehicles. It is a 5
way blue connector.
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual.
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment
ANTI-LOCK BRAKE SYSTEM - ABS
Manufactured by WABCO
Introduction
The purpose of ABS is to prevent vehicle wheels
locking during brake application, thus maintaining
vehicle steerability and stability. This allows vehicle to
be steered whilst brakes are applied, even under
emergency conditions, and to avoid obstacles where
there is sufficient space to redirect the vehicle.
WARNING: ABS is an aid to retaining
steering control and stability while
braking.
·ABS cannot defy the natural laws of physics
acting on the vehicle.
·ABS will not prevent accidents resulting from
excessive cornering speeds, following
another vehicle too closely or aquaplaning,
i.e. where a layer of water prevents adequate
contact between tyre and road surface.
·The additional control provided by ABS must
never be exploited in a dangerous or
reckless manner which could jeopardise the
safety of driver or other road users.
·The fitting of ABS does not imply that the
vehicle will always stop in a shorter stopping
distance.

70BRAKES
4
DESCRIPTION AND OPERATION System description
The brake system consists of dual hydraulic circuits in
a front - rear split. That is individual circuits to front
and rear axles.
Wheelspeed signals are provided by the fitting of
exciter rings to axles and speed sensors.
An ABS stop light switch is fitted to provide a braking
signal to the ECU as well as operate the stop lights.
Electrical wiring is provided as necessary with system
relays and fuses. Discovery Electrical Troubleshooting
Manual gives the location and wiring circuits of these
components.
Visual warning of system malfunction is provided via a
warning light in the instrument panel.
Hydraulic circuit ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve
D = ABS ModulatorABS System operation
During normal braking the feel of the brake pedal on
vehicles equipped with ABS will be the same as that
on non ABS vehicles. During ABS cycling the driver
will experience feedback in the form of a pulsating
brake pedal and solenoid/pump motor noise from the
Modulator.
The system is fully automatic in operation both on and
off road, and will only act when the ECU detects that
ABS cycling is necessary. The ECU continually
monitors the operation of the system.
When starting the ABS system will go through a series
of self checks, including a check of the solenoid
valves/pump motor.
WARNING LIGHT
The warning light will be on during the self check
(1.3-2 secs). If no faults are stored in the memory the
light goes out for 0.5sec,then comes on again. It will
then remain on until the vehicle is driven faster than 7
kph/5mph. This is the only time that the light will be on
without indicating a problem.
Any faults detected by the ECU will cause the warning
light to illuminate indicating that the vehicle may not
have full ABS control.

BRAKES
1
FAULT DIAGNOSIS ABS FAULT DIAGNOSIS
If a fault has occurred, or has been identified by ECU
self diagnostic function and ABS warning light is
illuminated. The system and components must be
checked to locate and rectify fault, using Testbook
diagnostics.
NOTE: If warning lamp has indicated a
fault in system, and no fault code has been
stored in memory, cause of fault is:
a) Failure in electrical supply
b) Bad ECU ground
c) Faulty warning light relay
d) ECU not connected
Before commencing fault diagnosis procedure
following items must be checked:
1.Inspect all exposed cables for damage or
abrasion.
2.Check ground on ABS system.
3.Battery - state of charge.
4.Check hub end-float.
5.All ABS fuses and electrical connections.
Fault rectification
1.Complete harness should be replaced if faults
are found in wiring harness.
2.DO NOT use unspecified cables or connectors,
as this could jeopardise safe function of ABS.
3.DO NOT attempt to open sealed 35 way
connector to ECU.FAULT DIAGNOSIS PROCEDURE
NOTE: If ABS warning light illuminates due
to large sensor air gap, fault will be
retained by the ECU memory. Where wheel
sensors have been pushed fully home prior to
test, The ECU will indicate a fault that has been
rectified.
NOTE: After any steering adjustment,
bearing replacement/adjustment, brake
disc replacement: Check hub end-float and
sensor clearance.
RELAYS AND FUSES ABS
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment

70BRAKES
2
FAULT DIAGNOSIS ABS FAULT AND REMEDY CHART
SYMPTOM POSSIBLE CAUSE CHECK REMEDY
ABS warning light on ABS electrical fault Check ABS electrical
circuit with Testbook
diagnostic equipmentChange component if
necessary
High sensor air gaps Push in sensors
Brake fluid warning light
ONFluid loss Check reservoir fluid level
and inspect system for
leaksRectify leakage, refill
reservoir
Reservoir fluid level
switch malfunctionCheck fluid level switch Change reservoir
cap/switch
Pedal travel increased,
foot pressure normalAir in system Rebleed brake system
Master cylinder
malfunctionChange master cylinder
Pedal can be moved
downwards under
constant pressureSeal leaking in master
cylinderInspect system for leaks Change master cylinder
Seal leaking in servo unit Change servo unit