ECU LAND ROVER DISCOVERY 1995 Workshop Manual

64REAR SUSPENSION
2
REPAIR BUMP STOP
Service repair no - 64.30.15.
Remove
1.Remove fixings.
2.Remove bump stop.
Refit
3.Position bolts in slots in bracket.
4.Fit bump stop secure with washer and nuts.SUSPENSION LINK UPPER
Service repair no - 64.35.44.
Remove
1.Support rear of chassis on stands, allow axle to
hang freely.
2.Remove fixings, upper link bracket to frame.
3.Remove fixings, upper links to pivot bracket.
4.Remove upper link complete with frame bracket.
5.Remove bolt.
6.Separate link from bracket.

64REAR SUSPENSION
4
REPAIR ANTI-ROLL[SWAY] BAR ASSEMBLY REAR
Service repair no - 64.35.08.
KEY
1. Anti-roll[sway] bar
2. Rubber bush
3. Strap
4. Nut, bolt, washer5. Nut and washer
6. Ball joint link arm
7. Bolt and washer
8. Castellated nut and cotter pin
Remove
1.Note for reassembly, position of rubber bushes
on anti-roll bar.
2.Remove four nuts, bolts and washers securing
two bush straps.
3.Remove nuts, bolts, washers and rubber bushes
from the ball joint links and remove anti-roll bar.Refit
4.Position rubber bushes on anti-roll bar. Fit joint
towards axle.
5.Fit anti-roll bar with two straps. Ensure ball joint
link arms point down as shown. Loosely fit, bolts,
washers and new nyloc nuts.
6.Fit bolt, washers and rubber bushes. Fit anti-roll
bar to ball joint links. Tighten to
68Nm.
7.Tighten nuts securing straps to30Nm.

REAR SUSPENSION
5
REPAIR ANTI-ROLL[SWAY] BAR BALL JOINT LINKS
Service repair no - 64.35.24.
Remove
1.Remove two nuts, bolts, washers and rubber
bushes from ball joint links and lower anti-roll bar
to clear links.
2.Remove cotter pin and loosen castellated nut a
few turns.
3.Release ball joint using special tool 18G 1063A
as shown.
4.Remove castellated nut and ball joint link.
Refit
5.Fit ball joint link arm and castellated nut. Point
ball joint link arm down as shown. Tighten to
40Nmand fit new cotter pin.
6.Align anti-roll bar to ball joint links.
7.Fit bolts, washers and rubber bushes using new
self locking nuts secure anti-roll bar to ball joint
links. Tighten to
68Nm.

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

BRAKES
3
REPAIR MASTER CYLINDER ABS
Service repair no - 70.30.08
- Lucas Girling - Type 25.4mm CV/CV
NOTE: This master cylinder is identified by
a 3rd plugged outlet port protruding down
from the master cylinder body.
Before starting repair refer to general brake service
practice.
See General Brake Service Practice
Remove
1.Disconnect battery negative lead.
2.Place a suitable container under master cylinder
to catch brake fluid from cylinder when brake
pipes are disconnected.
3.Thoroughly clean immediate area around all
outlet ports. Remove each brake pipe, sealing
each pipe and outlet port with suitable plugs to
prevent ingress of foreign matter.
4.Disconnect electrical plug from low fluid switch
on reservoir cap.
5.Remove two nuts securing master cylinder to
servo unit remove also spring and plain washers.
6.Detach master cylinder from servo, remove
reservoir cap and drain brake fluid into a
container.Refit
NOTE: Ensure O ring seal between master
cylinder and servo unit is fitted correctly.
7.Fit master cylinder to servo. Secure in position
with two nuts, plain and spring washers. Tighten
to
26 Nm.
8.Fit brake pipes to master cylinder. Tighten to
15Nm.
9.Top-up master cylinder with correct grade of
brake fluid.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
10.Bleed system.See Brake System Bleed
11.Fit cap, reconnect electrical lead to fluid level
switch. Reconnect battery negative lead.

70BRAKES
4
REPAIR MASTER CYLINDER NON ABS
Service repair no - 70.30.08 - Remove
Service repair no - 70.30.09 - Repair
- Lucas Girling - Type 25.4mm AS/AS
WARNING: This master cylinder is not
suitable to be fitted on vehicles with
antilock brake systems.
Before starting repair refer to general brake service
practice.
See General Brake Service Practice
Remove
1.Disconnect battery negative lead.
2.Place a suitable container under master cylinder
to catch brake fluid from cylinder when brake
pipes are disconnected.
3.Thoroughly clean immediate area around all
outlet ports. Remove each brake pipe, sealing
each pipe and outlet port with suitable plugs to
prevent ingress of foreign matter.
4.Disconnect electrical plug from low fluid switch
on reservoir cap.
5.Remove two nuts securing master cylinder to
servo unit remove also spring and plain washers.
6.Detach master cylinder from servo, remove
reservoir cap and drain brake fluid into a suitable
container.Repair
7.Thoroughly clean master cylinder and inspect
outer surfaces for damage and condition, renew
complete assembly if necessary.
8.Using two soft jaws, clamp master cylinder
flange in a suitable vice. Remove water ingress
'O' ring seal from master cylinder to servo flange
and discard.
9.Grip outside of transfer housing with a suitable
pair of pliers, carefully pull, working pliers in a
backwards and forwards rocking motion to ease
housing off master cylinder. Discard housing and
vacuum seal.

70BRAKES
6
REPAIR
NOTE: The primary plunger assembly
cannot be broken down any further and is
serviced as a complete unit. Discard
assembly.
15.The secondary plunger assembly will remain at
bottom of master cylinder bore. Remove tapping
assembly on a piece of wood until plunger
appears at cylinder mouth, carefully pull plunger
out of master cylinder.
16.If swirl tube was not expelled at same time as
secondary plunger, repeat above operation to
remove it from bottom of master cylinder bore
and discard.
17.Clean all parts with unused brake fluid. Place
cleaned parts onto a clean sheet of paper.
Inspect cylinder bore and plungers for signs of
corrosion, ridges and score marks. Provided
working surfaces are in perfect condition, new
seals from a Girling Service repair kit may be
used.
Renewing secondary plunger seals
18.Remove following components from secondary
plunger and discard:
NOTE: A small screwdriver with end
rounded off and polished is required to
remove 'L' seal. DO NOT damage
secondary plunger.
(A) Springs
(B) Seal retainer
(C) Recuperating seal (primary cup)
(D) Washer
(E) 'L' seal

BRAKES
7
REPAIR 19.Coat new seals in unused brake fluid. Fit 'L' seal
to plunger.
20.Fit washer followed by recuperating seal. Fit seal
retainer and springs, ensure springs are
correctly seated.
Assembling master cylinder
CAUTION: It is important that following
instructions are carried out precisely,
otherwise damage could be caused to new
seals when inserting plungers into cylinder bore.
Generous amounts of new brake fluid should be
used to lubricate parts during assembly.
21.Fit new swirl tube to bottom of cylinder bore.
22.Lubricate secondary plunger and cylinder bore.
Offer plunger assembly to cylinder until
recuperation seal is resting centrally in mouth of
bore. Gently introduce plunger with a circular
rocking motion, as illustrated. Ensuring that seal
does not become trapped, ease seal into bore
and slowly push plunger down bore in one
continuous movement.
23.Fit new primary plunger assembly using same
method as for secondary plunger.
24.Fit original guide ring to support primary plunger.
25.Coat a new 'O' ring with brake fluid and fit to its
respective groove on outer location surface of
master cylinder.
CAUTION: Do not roll 'O' ring down outer
location surface of master cylinder. It
should be slightly stretched and eased
down cylinder and into its groove. Do not over
stretch seal.
26.Fit new retaining ring on outer surface of master
cylinder ensuring that serrations of ring are
facing mounting flange.
27.Fit two new reservoir seals in respective ports.
28.Fit a new vacuum seal to either primary plunger
or to bottom of transfer housing bore, open face
of seal towards primary plunger.
29.Lubricate vacuum seal with brake fluid. Fit
transfer housing to master cylinder, push
housing fully up to cylinder mounting flange, Do
not adjust transfer housing after fitting.
30.Lubricate new water ingress seal with brake
fluid, Slightly stretch seal and ease down
housing until it is in position between housing
and flange.
31.Roll reservoir into top of master cylinder,
reversing procedure described in instruction 10.
Refit
NOTE: Ensure O ring seal between master
cylinder and servo unit is fitted correctly.
32.Fit master cylinder to servo. Secure in position
with two nuts, plain and spring washers. Tighten
to
26 Nm.
33.Fit brake pipes to master cylinder. Tighten to
15Nm.
34.Top-up master cylinder with correct grade of
brake fluid.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
35.Bleed system.See Brake System Bleed
36.Fit cap, reconnect electrical lead to fluid level
switch. Reconnect battery negative lead.