REAR SUSPENSION
1
DESCRIPTION AND OPERATION AXLE LOCATION
Longitudinal location of the rear axle is by solid round section steel link arms and a forged "A" frame, upper link
assembly, which is secured to a chassis cross member and provides transverse control. Long travel coil springs
and hydraulic shock absorbers provide the springing for each wheel.
Rear axle suspension
1. "A" frame, upper link assembly - transverse location
2. Lower link assembly - longitudinal location
3. Coil springs
4. 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
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
10
REPAIR FRONT BRAKE PADS
Service repair no - 70.40.02
Service tool:
LRT.70-500 - Piston clamp
Remove
1.Remove front road wheels.
See WHEELS AND
TYRES, Repair, Wheels
2.Clean exterior of calipers.
3.Remove split [cotter] pin from retaining pins.
4.Remove pad retaining pins and anti-rattle
springs.
5.Remove brake pads.
6.Clean exposed parts of pistons, using new brake
fluid. Wipe away excess with a lint free cloth.
7.Using piston clamp LRT-70-500 press each
piston back into its bore. Ensure that displaced
brake fluid does not overflow from reservoir.
Refit
8.Fit brake pads.
9.Fit pad retaining pins and anti-rattle springs.
Secure with new split [cotter] pin.
10.Apply service brake pedal several times to locate
pads.
11.Check fluid reservoir. Top up if necessary, using
correct grade of fluid.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids
BRAKES
11
REPAIR REAR BRAKE PADS
Service repair no - 70.40.03
Service tool:
LRT-70-500 - Piston clamp
Remove
1.Remove rear road wheels.
See WHEELS AND
TYRES, Repair, Wheels
2.Disconnect battery negative lead.
3.Clean exterior of calipers.
4.Remove pad retaining pins and springs.
5.Remove brake pads.
6.Clean exposed parts of pistons, using new brake
fluid. Wipe away excess with a lint free cloth.
7.Using piston clamp LRT-70-500 press each
piston back into its bore. Ensure that displaced
brake fluid does not overflow from reservoir.Refit
8.Insert brake pads.
9.Position pad retaining springs, fit new pins and
spread ends.
10.Apply service brake pedal several times to locate
pads.
11.Check fluid reservoir, top up if necessary, using
correct grade of fluid.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids
BRAKES
13
REPAIR FRONT BRAKE CALIPERS
Service repair no - 70.55.03
Service repair no - 70.55.16
Service tool:
LRT-70-500 - Piston clamp
Before starting repair refer to general brake service
practice.
See General Brake Service Practice
Remove caliper
1.Loosen front wheel retaining nuts, raise front of
vehicle, lower onto axle stands, remove wheels.
2.Expose flexible brake hose by moving coiled
protective covering.
3.Using a recognised hose clamp, clamp hose to
prevent loss of brake fluid.
4.Disconnect rigid brake pipe from flexible hose,
seal exposed ends to prevent ingress of dirt.
5.Remove split [cotter] pin, retaining pins and
springs, withdraw pads. If refitting pads, identify
them for assembly to original locations.
6.Loosen bolts and remove caliper.
Repair
Do not separate caliper halves
7.Clean outer surfaces of caliper using aerosol
brake cleaner.
8.Using special tool LRT-70-500, clamp pistons in
inboard half of caliper. Gently, keeping fingers
clear, and withCAUTION,apply air pressure to
fluid inlet port to expel pistons. It is unlikely that
pistons will expel at same time, regulate rate
with a suitable piece of wood between
appropriate piston and caliper.
9.Finally remove pistons, identifying them with
their respective bores.
10.Remove wiper seal retainer by inserting a blunt
screwdriver between retainer and seal. Pry
retainer carefully from mouth of bore.
11.Taking care not to damage seal grooves, extract
wiper seal and fluid seal.
12.Clean bores, pistons and seal grooves using
clean brake fluid only. If caliper or pistons are
corroded, or their condition is not perfect, new
parts must be fitted.