1995 LAND ROVER DISCOVERY ABS

70BRAKES
8
REPAIR MASTER CYLINDER ASSEMBLY NON ABS
Key to master cylinder
1. Water ingress seal
2. Transfer housing
3. Vacuum seal
4. Guide ring
5. Retaining ring
6. 'O' ring seal7. Primary plunger assembly
8. 'L' seal
9. Secondary plunger
10. Washer
11. Recuperating seal (primary
cup)
12. Seal retainer13. Springs (2 off)
14. Swirl tube
15. Master cylinder body
16. Reservoir seals
17. Reservoir
18. Low fluid level switch and
cap
NOTE: Thoroughly check that no debris is lodged in fluid passageways and drillings. If debris is
found, carefully remove, re-clean cylinder and re-check.

70BRAKES
18
REPAIR SENSORS - FRONT
Service repair no - 70.65.32
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush and seal must
be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect required sensor electrical
connection, located on inner wing [fender] panel.
3.Remove sensor lead from clips.
4.Clean area surrounding sensor to prevent
ingress of dirt. Using a suitable lever pry sensor
from mounting bush.
5.Release harness cable ties, remove sensor lead
from vehicle.
6.Remove top swivel retaining bolts complete with
brake jump hose and sensor seal. Remove
sensor bush.
Refit
7.Insert new sensor bush and seal.
8.Refit brake jump hose bracket, coat bolts with
Loctite 270.
9.Lightly coat new sensor using EP 90 oil. Push
sensor through bush until it contacts exciter ring.
Sensor will be 'knocked back' to correct position
when vehicle is driven.
10.Secure sensor lead in original position.
11.Reconnect sensor electrical connection.
12.Drive vehicle to ensure ABS warning light is
extinguished.
SENSOR RINGS
The rear sensor ring is assembled to the rear brake
disc to form part of the rear hub assembly.
See
REAR AXLE AND FINAL DRIVE, Repair, Rear Hub
Assembly
The front sensor ring is a toothed ring on the axle
shaft which forms part of the front stub axle assembly.
See FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS

BRAKES
19
REPAIR SENSORS - REAR
Service repair no - 70.65.31
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush must be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect sensor electrical connections,
located above rear axle.
3.Remove sensor from its locating clip.
4.Remove bolts securing mudshield.
5.Using a suitable lever, pry sensor from mounting
bush.
6.Release harness cable ties, remove sensor lead
from vehicle.
7.Remove sensor bush.
Refit
8.Fit new sensor bush.
9.Lightly grease new sensor using silicone grease.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
10.Push sensor through bush until it touches exciter
ring. Sensor will be 'knocked back' to correct
position when vehicle is driven.
11.Secure harness in position.
12.Reconnect sensor electrical connection.
13.Drive vehicle to ensure ABS warning light is
extinguished.STOP LIGHT SWITCH ABS
Service repair no - 86.65.51
Remove
1.Turn ignition off. Disconnect battery negative
lead.
2.Remove lower trim panel.
3.Disconnect multiplug to switch.
4.Depress brake pedal access front of switch.
5.Pull sleeve and plunger of switch FULLY
forward.
6.Remove switch rearwards
NOTE: If switch is difficult to release,
check sleeve is FULLY forward.
Refit
7.Pull sleeve and plunger of switch fully forward.
8.Depress brake pedal, fit switch. Ensure retaining
clips are FULLY located.
9.Hold switch firmly in place, pull brake pedal back
fully to set switch.
10.Reconnect battery and turn ignition on.
11.Check switch operation by slowly depressing
brake pedal and checking that the switch clicks
twice.
12.Check stop lamps go off when pedal is released.
13.Recheck switch is securely fitted.
14.Operation may be checked using Testbook.

70BRAKES
20
REPAIR STOP LIGHT SWITCH - NON ABS
Service repair no - 86.65.51
Remove
1.Disconnect battery negative lead.
2.Remove lower dash panel.
3.Depress foot brake.
4.Remove rubber protector from switch, if fitted.
5.Remove hexagon nut.
6.Withdraw switch.
7.Disconnect electrical leads.
Adjust
8.With switch still in position and multiplug
disconnected, connect an ohmmeter across
switch terminals.
9.Screw switch in until open circuit exists across
terminals with pedal released and continuity
exists as soon as pedal is depressed.
10.Tighten locknut.
CAUTION: Ensure switch does not prevent
brake pedal returning fully.
Refit
11.Reverse removal procedure.

BRAKES
21
REPAIR BRAKE COMPONENTS 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
22
REPAIR MODULATOR UNIT
Service repair no - 70.65.45
WARNING: New modulator units are
supplied in a shock absorbing pack
marked with a use by date. The new
modulator will contain hydraulic brake fluid within
the valve block and all ports plugged.
Modulator units must be handled with care the
following must be avoided:- any impact, use of
compressed air on any of the hydraulic ports,
removing plugs to connection ports before fitting
unit.
Remove
1.Refer to the illustration of brake components
ABS. For details of modulator unit and hydraulic
pipe connections to it.
See Brake
Components ABS
2.Refer to general brake service practice.See
General Brake Service Practice
3.Check new modulator unit is packaged in
accordance with the WARNING above.
4.Disconnect battery negative lead.
5.Remove the two electrical plugs.
6.Identify 8 pipe to modulator connections for
correct reassembly.
7.Disconnect 8 pipe unions.
8.Remove nuts securing modulator to mounting
bracket.
9.Remove modulator unit.
10.Remove mounting bushes and cup.
Refit
11.Fit mounting bushes and cup to new modulator.
12.Fit modulator unit to mounting bracket.
13.Fit 8 pipes to modulator connections. Pipes
mustbe connected to correct port. Tighten to
15Nm.
14.Bleed the complete hydraulic system.See
Brake System Bleed
15.Check system function using the 'Testbook'
diagnostics
16.Test operation of brakes.ELECTRONIC CONTROL UNIT ABS
Service repair no - 70.65.01
Remove
For location of the ECU.
See Description and
operation, ABS Components
1.Disconnect battery negative lead.
2.Remove retaining bolt and lower alarm system
ECU and relay mounting bracket into passenger
footwell.
3.Remove two screws and detach ECU complete
with harness plug from mounting bracket.
4.Release ECU plug retaining clip.
5.Move plug in direction of arrow and release
hooked end of plug from retaining post.
Refit
6.Reconnect ECU harness plug ensuring that it is
firmly located and retaining clip secures plug.
7.Reverse removal procedure.

WHEELS AND TYRES
1
FAULT DIAGNOSIS TYRE WEAR CHART
FAULT CAUSE REMEDY
Rapid wear at Tyres under-inflated Inflate to correct pressure
shoulders Worn suspension components Replace worn components
i.e. ball joints, panhard
rod bushes,steering damper
Excessive cornering speeds
Rapid wear at
centreTyres over-inflated Inflate to correct pressure
of tread
Wear at one
shoulderTrack out of adjustment Adjust track to correct figure
Bent panhard rod Check and replace worn or damaged
components
Bald spots or tyre Wheel out of balance Balance wheel and tyre
cupping assembly
Excessive radial runout Check runout and replace tyre
if necessary
Shock absorber worn Replace shock
Excessive braking
Tyre scalloped Track out of adjustment Adjust toe to correct figure
Worn suspension components Replace as necessary
Excessive cornering speeds
CAUTION: This diagnosis chart is for general guidance only and does not necessarily include
every cause of abnormal tyre wear.

82AIR CONDITIONING
4
DESCRIPTION AND OPERATION 5. Evaporator
As this change of state occurs, a large amount of
latent heat is absorbed. The evaporator is therefore
cooled and as a result heat is extracted from the air
flowing across the evaporator. The air flow is
controlled by the ventilation fan which can be
operated at anyone of four speeds.
To prevent liquid passing through to the compressor,
a capillary tube (6), attached to the outlet pipe of the
evaporator (5) and connected to the thermostatic
expansion valve (4), controls the amount that the
valve opens and closes in relation to the temperature
of the low pressure high temperature refrigerant
vapour (F4) at the outlet. The atomised refrigerant
then passes through the evaporator (5). Fan blown air
(A2) passes through the matrix (A3) of the evaporator
and is cooled by absorption due to the low
temperature refrigerant passing through the
evaporator.
A thermostat is fitted in the airflow out of the
evaporator to sense the temperature of the exterior
fins. Should ice begin to form, due to a too cold
condition, it will signal to disengage the
electro-mechanical clutch on the compressor (1).
From the evaporator, low pressure slightly
superheated refrigerant (F5) passes to the
compressor to complete the cycle.AIR CONDITIONING CONTROL SYSTEM
The air conditioning control system comprises relays,
thermostat, pressure switches, and a control panel.
Inputs from outside the air conditioning system
comprise temperature information from the engine
cooling system. Together these controls, in
conjunction with the cooling fans, compressor clutch,
blower and heater distribution and blend unit enable
minimal input to maintain the required environment
inside the vehicle.
When air conditioning is not selected, air is supplied
by ram effect or blower to the areas selected by the
controls. The air mix flap on the blend unit controls the
temperature of the air being supplied. No cooled air is
available.
Selecting air conditioning provides the added facility of
cooled air available to be mixed as before. When
required a fully cold condition can be selected by
turning the temperature controls to cold, which
automatically closes the heated coolant access to the
heater matrix. Mixtures of cooled, fresh, and hot air
can be selected to give required interior environmental
conditions by selection at the control panel.
Dual pressure switch
This switch, located in the high pressure line between
the receiver drier and the expansion valve, monitors
refrigerant pressure and by means of the relay module
controls the following system functions:
1.Refrigerant pressure drops below 2.0 bar, 29
lbf/in
2(due to possible leakage), the
compressor's electro-mechanical clutch is
dis-engaged.
When pressure rises above 2.0 bar, 29 lbf/in
2the
compressor's clutch is re-engaged.
2.Refrigerant pressure rises above 32 bar, 455
lbf/in
2(due to possible blockage), even with
cooling fan operation, the compressor's
electro-mechanical clutch is dis-engaged.
When the pressure drops below 26 bar, 375
lbf/in
2the compressor clutch is re-engaged.