ABS LAND ROVER DISCOVERY 1995 Owners Manual

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.

82AIR CONDITIONING
2
ADJUSTMENT SERVICING PRECAUTIONS
Care must be taken when handling refrigeration
system components. Units must not be lifted by their
hoses, pipes or capillary lines. Hoses and lines must
not be subjected to any twist or stress. Ensure that
hoses are positioned in their correct run before fully
tightening the couplings, and ensure that all clips and
supports are used. Torque wrenches of the correct
type must be used when tightening refrigerant
connections to the stated value. An additional wrench
must be used to hold the union to prevent twisting of
the pipe.
Before connecting any hose or pipe ensure that
refrigerant oil is applied to the seat of the new '0' ring
but not to the threads.
Check the oil trap for the amount of oil lost.
All protective plugs on components must be left in
place until immediately prior to connection.
The receiver/drier contains desiccant which absorbs
moisture. It must be positively sealed at all times.
CAUTION: Whenever the refrigerant
system is opened, the receiver/drier must
be renewed immediately before evacuating
and recharging the system.
Use alcohol and a clean cloth to clean dirty
connections.
Ensure that all new parts fitted are marked for use
withR134a.
Refrigerant oil
Use the approved refrigerant lubricating oil:
Nippon Denso ND-OIL 8
Unipart R134a ND-OIL8
CAUTION: Do not use any other type of
refrigerant oil.
Refrigerant oil easily absorbs water and must not be
stored for long periods. Do not pour unused oil back
into the container.
When renewing system components, add the
following quantities of refrigerant oil:
Condenser 40ml..........................................................
Evaporator 80ml..........................................................
Pipe or hose 20ml........................................................
Receiver/drier 20ml......................................................
Total of refrigerant oil in system = 180ml = 6.3 Fl
ozA new compressor is sealed and pressurised with
Nitrogen gas, slowly release the sealing cap, gas
pressure should be heard to release as the seal is
broken.
NOTE: A new compressor should always
have its sealing caps in place and must
not be removed until immediately prior to
fitting
Fitting a new compressor
A new compressor is supplied with an oil fill (X) of:
180ml
A calculated quantity of oil must be drained from a
new compressor before fitting.
To calculate the quantity of oil to be drained:
1.Remove sealing plugs from the OLD compressor
2.Invert compressor and gravity drain oil into
measuring cylinder. Rotating the compressor
clutch plate will assist complete draining.
3.Note the quantity of oil drained (Y).
4.Calculate the quantity (Q) of oil to be drained
from the NEW compressor using the following
formula:
X - (Y + 20ml) = Q
Rapid refrigerant discharge
When the air conditioning system is involved in
accident damage and the circuit is punctured, the
refrigerant is discharged rapidly. The rapid discharged
of refrigerant will also result in the loss of most of the
oil from the system. The compressor must be
removed and all the remaining oil in the compressor
drained and refilled as follows:
1.Gravity drain all the oil, assist by rotating the
clutch plate (not the pulley).
2.Refill the compressor with the following amount
of new refrigerant oil:
130ml
3.Plug the inlet and outlet ports.

AIR CONDITIONING
1
REPAIR PRECAUTIONS IN HANDLING REFRIGERANT
LINES
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
1.When disconnecting any hose or pipe
connection the system must be discharged of all
pressure. Proceed cautiously, regardless of
gauge readings. Open connections slowly,
keeping hands and face well clear, so that no
injury occurs if there is liquid in the line. If
pressure is noticed, allow it to bleed off slowly.
2.Lines, flexible end connections and components
must be capped immediately they are opened to
prevent the entrance of moisture and dirt.
3.Any dirt or grease on fittings must be wiped off
with a clean alcohol dampened cloth. Do not use
chlorinated solvents such as trichloroethylene. If
dirt, grease or moisture cannot be removed from
inside the hoses, they must be replaced with
new hoses.
4.All replacement components and flexible end
connections must be sealed, and only opened
immediately prior to making the connection.
5.Ensure the components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters.
6.Components must not remain uncapped for
longer than fifteen minutes. In the event of delay,
the caps must be fitted.
7.Receiver/driers must never be left uncapped as
they contain Silica Gel crystals which will absorb
moisture from the atmosphere. A receiver/ drier
left uncapped must not be used, fit a new unit.
8.The compressor shaft must not be rotated until
the system is entirely assembled and contains a
charge of refrigerant.
9.A new compressor contains an initial charge of
of refrigerant oil. The compressor also contains a
holding charge of gas when received which
should be retained by leaving the seals in place
until the pipes are re-connected.10.The receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection of
the system.
11.All precautions must be taken to prevent
damage to fittings and connections. Slight
damage could cause a leak with the high
pressures used in the system.
12.Always use two wrenches of the correct size,
one on each fitting when releasing and
tightening refrigeration unions.
13.Joints and 'O' rings should be coated with
refrigeration oil to aid correct seating. Fittings
which are not lubricated with refrigerant oil are
almost certain to leak.
14.All lines must be free of kinks. The efficiency of
the system is reduced by a single kink or
restriction.
15.Flexible hoses should not be bent to a radius
less than 90mm.
16.Flexible hoses should not be within 100mm of
the exhaust manifold.
17.Completed assemblies must be checked for
refrigeration lines touching metal panels. Any
direct contact of lines and panels transmits noise
and must be eliminated.

86ELECTRICAL
2
REPAIR FUSE BOX - ENGINE COMPARTMENT
The fusebox is located on the right side of the engine compartment. The circuits protected and their locations are
shown on the inside of the fusebox cover. To change a main circuit fuse prise off protective cover A and remove
retaining screws.
Fuses
1. Heated rear window
2. Sidelights
3. Air conditioning
4. Hazard warning lights, horn
5. ABS valve
6. Fuel pump
7. Fuel injectors
A Main circuit fuses
8. ABS pump
9. Ignition circuits
10. Lighting
11. Window lift, central door locking, rear blower
12. Heater, air conditioning
13. Generator

86ELECTRICAL
34
REPAIR PRINTED CIRCUIT AND WARNING LIGHTS
1. Panel illumination bulbs
2. Transmission oil temperature warning lamp bulb
3. Hazard warning lamp bulb
4. Check engine warning lamp bulb
5. Handbrake/brake fluid warning lamp bulb
6. ABS warning lamp bulb
7. Headlamp main beam warning lamp bulb
8. Trailer direction warning lamp bulb9. Direction indicator warning lamp bulb
10. Air suspension warning lamp bulb
11. Ignition/no charge warning lamp bulb
12. Seat belt warning lamp bulb
13. Not used
14. Traction control warning lamp bulb
15. Diesel heater plug warning lamp bulb (if fitted)
16. Main printed circuit