brake LAND ROVER DISCOVERY 1995 Owners Manual

STEERING
1
ADJUSTMENT POWER STEERING BOX
Service repair no - 57.10.13
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is stiff or tight and within
warranty, it must be returned to manufacturer. No
attempt must be made to introduce backlash.
1.Apply park brake, select 'P' in automatic
transmission and chock wheels. Support chassis
front on axle stands.
2.Remove engine undertray.
3.Disconnect drag link from steering drop arm.
4.Check torque to turn.
See Fault diagnosis,
Stiff Steering Checklist
5.Centralise steering box.See Centralise
Steering Box
NOTE: Only check for no backlash when
steering box is in central position.
NOTE: If steering wheel is not straight, it
should be repositioned.
See Repair,
Steering Wheel
The adjustment of the steering box ensures
any preload or end float present on centre is
removed.
6.The adjustment is obtained by rocking the drop
arm about centre whilst an assistant slowly
tightens the steering box adjuster screw.
7.Tighten the locknut when all backlash has been
removed.
8.Repeat the check for backlash. If backlash exists
loosen locknut and repeat adjustment
procedure.
9.Turn steering wheel lock to lock and check no
tightness exists.
10.Ensure front wheels are aligned and in straight
ahead position.
See Front Wheel Alignment
11.Adjust drag link 924 mm between ball joint
centres.
12.Connect drag link. Tighten to
40 Nm.
13.Lower vehicle to ground level and remove
chocks.
14.Road test vehicle.
See Fault diagnosis, Road
Test Procedure
NOTE: If steering wheel is not in straight
ahead position when vehicle is travelling
in a straight line, drag link length is
incorrect and is pushing drop arm away from
central position.
Drag link adjust
15.Right hand drive vehicles - if steering wheel is to
right, drag link is too long. If steering wheel is to
left drag link is too short.
Left hand drive vehicles - if steering wheel is to
right, drag link is too short. If steering wheel is to
left drag link is too long.
16.Adjust drag link until steering wheel points
straight ahead when vehicle is travelling in a
straight line.
CENTRALISE STEERING BOX
1.To centralise the box, insert a suitable peg (hole
size 8.06 mm) into the rear of the drop arm and
into the steering box casing to enable rapid and
accurate setting on centre.

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.

FRONT SUSPENSION
3
REPAIR 7.Withdraw lower seating washer, rubber bush and
cupwasher.
8.Remove fixings, shock absorber to mounting
bracket.
9.Withdraw mounting bracket.
10.Lift off top seating washer, rubber bush and
cupwasher.
Refit
11.Reverse removal procedure. 1 to 10.FRONT ROAD SPRING
Service repair no - 60.20.11.
Remove
1.Remove front shock absorber.
See Front
Shock Absorber
CAUTION: Avoid over stretching brake
hoses. If necessary loosen hose connector
locknuts to allow hoses to follow axle.
2.Lower axle sufficient to free road spring.
3.Withdraw road spring.
4.Withdraw shock absorber bracket securing ring.
Refit
5.Fit shock absorber bracket retaining ring. Retain
in position with a nut.
6.Reverse 2 and 3.
7.Remove nut retaining securing ring.
8.Fit front shock absorber.

REAR SUSPENSION
1
REPAIR REAR ROAD SPRING
Service repair no - 64.20.01
Remove
1.Loosen rear road wheel retaining nuts.
2.Support chassis on stands and remove wheels.
3.Support rear axle weight with jack.
4.Disconnect shock absorbers at one end.
5.Position coil spring compressor correctly on road
spring.
6.Compress spring evenly to facilitate removal.
7.Lower axle to free road spring from upper seat.
CAUTION: Avoid lowering axle further than
rear brake flexible hose will allow.
8.Remove spring retainer plate.
9.Withdraw road spring, and spring isolator.
10.Lift off spring seat.
Refit
11.Reverse removal procedure.REAR SHOCK ABSORBER
Service repair no - 64.30.02.
Remove
1.Loosen road wheel retaining nuts.
2.Support chassis on stands. Remove road wheel
and support rear axle weight with jack.
3.Remove fixings and withdraw shock absorber
from axle bracket.
4.Remove upper fixings.
5.Withdraw shock absorber.
6.If required remove mounting bracket
7.If required remove mounting rubbers.
Refit
8.Reverse removal procedure.

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

70BRAKES
2
DESCRIPTION AND OPERATION ABS COMPONENTS
Location
Key to diagram
1. ABS Modulator unit
2. Servo/Master cylinder
3. Pressure reducing valve
4. Electronic control unit5. Rear sensors/exciter rings
6. Front sensors/exciter rings
7. Diagnostic plug connection

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
5
DESCRIPTION AND OPERATION BRAKE PIPE LAYOUT ABS
Left hand drive shown. On right hand drive vehicles the master cylinder and servo unit only move
position.
KEY
1. Connector double elbow
2. Rear left brake
3. Modulator to rear left brake
4. Modulator to master cylinder
5. Modulator to pressure reducing valve upper
6. Electrical connection
7. Modulator unit
8. Nut, mounting bush and cup
9. Modulator to front left brake
10. Front left brake
11. Electrical connection12. Modulator to front right brake
13. Modulator to pressure reducing valve lower
14. Master cylinder to pressure reducing valve lower
15. Front right brake
16. Bolt
17. Pressure reducing valve
18. Modulator to pressure reducing valve upper
19. Master cylinder
20. Servo unit
21. Modulator to rear right brake
22. Rear right brake

70BRAKES
6
DESCRIPTION AND OPERATION BRAKE PIPE LAYOUT NON ABS
Left hand drive shown. On right hand drive vehicles the master cylinder and servo unit only move
position.
KEY
1. T-Connector
2. Rear left brake
3. Master cylinder to pressure reducing valve lower
4. Front left brake to pressure reducing valve upper
5. Front left brake
6. Front right brake
7. Master cylinder to pressure reducing valve lower8. Pressure reducing valve
9. Front right brake to pressure reducing valve
upper
10. Master cylinder
11. Servo unit
12. Pressure reducing valve upper to both rear
brakes
13. Rear right brake