electrical LAND ROVER DISCOVERY 1995 Repair Manual

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.

BRAKES
9
REPAIR SERVO ASSEMBLY
Service repair no - 70.50.01
Remove
Before starting repair refer to general brake service
practice.
See General Brake Service Practice
NOTE: The filter, non-return valve and
grommet, are the only serviceable
components, in event of failure or damage
fit a new unit.
1.Disconnect battery negative lead.
2.Disconnect electrical plug to low fluid level
switch.
3.Thoroughly clean immediate area around all
master cylinder outlet ports. Remove each brake
pipe, sealing each pipe and outlet port to prevent
ingress of foreign matter.
4.Disconnect vacuum supply hose to servo.
5.Remove lower dash panel to gain access to
servo push rod to brake pedal.
6.Remove clevis pin securing servo push rod to
brake pedal.
7.Remove two nuts and plain washers securing
servo.
8.Remove servo and master cylinder assembly.
9.Drain brake fluid into a suitable container. (If
master cylinder is kept horizontal it is not
necessary to drain fluid).10.Detach spacer from pedal box mounting face of
servo.
NOTE: Retain spacer for reassembly. The
spacer ensures stringent pedal to servo
operating dimensions are maintained.
11.Remove master cylinder from existing servo and
refit to new servo, if fitting new unit.
Refit
12.Fit spacer to servo.
13.Fit servo to pedal box.
14.Lightly grease brake pedal around area servo
push rod pivots.
15.Fit push rod to lower hole of brake pedal. Fit
clevis pin and clip.
16.Secure servo with two nuts and plain washers.
Tighten nuts to
26 Nm.
17.Refit lower dash panel.
18.Fit master cylinder to servo, refit nuts, plain and
spring washers. Tighten nuts to
26 Nm.
19.Remove all sealing plugs. Refit brake pipes to
respective ports. Tighten brake pipes to
15 Nm.
20.Refit vacuum supply hose.
21.Fill master cylinder to correct level using correct
grade of brake fluid.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids
22.Bleed brake system.See Brake System Bleed

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.

SUPPLEMENTARY RESTRAINT SYSTEM
3
DESCRIPTION AND OPERATION SRS warning light (airbag)
Distributed SRS
The warning light in the instrument pack illuminates
after the electrical circuits are switched on whilst a
system check is carried out. After about 8 seconds the
warning light will go out. The system checks airbag
diagnostic control unit, airbag crash sensors, airbag
harness, driver and passenger modules.
SPS SRS
The warning light in the instrument pack illuminates
after the electrical circuits are switched on whilst a
system check is carried out. After about 5 seconds the
warning light will go out. The system checks airbag
diagnostic control unit, airbag harness, driver and
passenger modules.
All Models
In the event of a fault in the system the warning light
will illuminate. The airbag diagnostic control unit logs
the fault which can only be accessed using TestBook.

SUPPLEMENTARY RESTRAINT SYSTEM
5
DESCRIPTION AND OPERATION
7.Do not use electrical test equipment on the
airbag harness or connectors. Tampering with or
disconnecting the harness could result in
accidental firing of the airbag or make the
system inoperative, which may result in serious
injury.
8. An airbag system fault can only be
diagnosed using TestBook.
9.The airbag module contains Sodium Azide which
is poisonous and extremely flammable. Contact
with water, acid or heavy metals may produce
harmful or explosive compounds. Do not
dismantle, incinerate or bring into contact with
electricity.VEHICLE RECOVERY
Towing - airbag not deployed
Normal towing procedures are unlikely to cause an
airbag to deploy. However, as a precaution switch the
ignition off and then disconnect both battery leads.
Disconnect the negative '-' lead first.
Towing - airbag deployed
Once the driver's airbag has been deployed the
vehicle must have a front suspended tow. However,
as a precaution switch the ignition off and then
disconnect both battery leads. Disconnect the
negative '-' lead first.

SUPPLEMENTARY RESTRAINT SYSTEM
1
FAULT DIAGNOSIS CRASH SENSOR INSPECTION - DISTRIBUTED
SRS
1.After any degree of front body damage, inspect
both front crash sensors. Replace a sensor if
there are any signs of dents, cracks or
deformation.
2.Ensure the sensors are installed correctly. There
must be no gap between the sensor and body of
the vehicle. Use the fixing screws supplied with
the sensor and tighten to the correct torque.
Tighten front sensor fixing before rear sensor
fixing.
CAUTION: Take extra care when painting
or doing body work in the vicinity of the
sensors. Avoid direct exposure of the
sensors or harness to heat guns, welding or
spraying equipment.AIRBAG HARNESS
1.Never attempt to modify, splice or repair the
airbag harness. Never install electronic
equipment such as; a mobile telephone, two-way
radio or in-car entertainment system in such a
way that it interferes electrically with the airbag
harness.
NOTE: The airbag harness can be
identified by a special yellow outer
protective covering.
2.Make sure the airbag harness is installed
correctly and not pinched or trapped.
3.Ensure all airbag harness connectors are mated
correctly and securely fastened. Do not leave the
connectors hanging loose.