wheel LAND ROVER DISCOVERY 1995 Repair Manual

CRUISE CONTROL
1
DESCRIPTION AND OPERATION CRUISE CONTROL COMPONENT LOCATIONS -
Tdi AUTO EDC
COMPONENT LOCATION
1. Cruise control unit Under LH dash...................................................
2. Engagement (on/off) switch Dash panel....................................
3. Cruise control switch Steering wheel...............................................
4. Rotary coupler Steering wheel.........................................................
5. Vacuum pump Box section under jack.........................................................
6. Brake/vent switch Brake pedal....................................................
7. Vehicle speed sensor Transfer box behind transmission brake..............................................
8. Neutral lock-out relay Behind RH lower 'A' post trim casing..............................................
9. Actuator RH engine compartment...................................................................

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION CRUISE CONTROL SYSTEM - V8i/Tdi AUTO EDC
Description
The cruise control system consists of
electro-mechanical devices, and comprises of the
following components.
ELECTRONIC CONTROL UNIT (ECU)
The microprocessor based ECU evaluates the signals
provided by the driver controls, brake pedal switch,
clutch pedal switch on manual models, and the
vehicle speed sensor. The ECU activates the vacuum
pump as required. The ECU also has a memory
function for set speed storage.
Driver operated switches
The main cruise control switch is located in the
auxiliary switch panel and activates the cruise control
system. The steering wheel switches provide
'set/accelerate' and 'resume/decelerate' features.
These switches provide the interface between driver
and cruise control system.
Brake pedal switch
The brake pedal switch is located under the lower
dash attached to the brake pedal mounting bracket.
The switch provides for fast disengagement of the
cruise control system and rapid return of the throttle
levers to the idle position when the brake pedal is
applied.
Clutch pedal switch
The clutch pedal switch is located under the lower
dash attached to the clutch pedal mounting bracket.
The switch provides for fast disengagement of the
cruise control system and rapid return of the throttle
levers to the idle position when the clutch pedal is
applied.Vehicle speed sensor
The vehicle speed sensor is located on the side of the
transfer box adjacent to park brake. The sensor
provides road speed data to the ECU. The cruise
control system cannot be engaged until the road
speed exceeds 45 km/h, (28 mph) the system will
automatically disengage at a road speed of 42 km/h
(26 mph).
Vacuum pump
The vacuum pump is energised when the main cruise
control switch is operated, and is actuated by the
steering wheel and brake pedal switches. The pump
provides a vacuum source to the cruise control
actuator. A control valve in the pump provides for
steady increase of road speed or purge of the system
when the brake pedal is applied.
Actuator
The actuator provides the servo mechanism link
between the cruise control system and throttle linkage
and is operated by vacuum from the vacuum pump.
Neutral lockout relay - automatic vehicles
The relay module is located in the right hand side
footwell, accessible by removing the trim casing.
The function of the relay module is to disengage the
cruise control system if neutral, or park, is selected in
the main gearbox, when the system is engaged.
Engine speed trip ECU - Manual vehicles
This unit is located in the right hand side footwell,
accessible by removing the trim casing.
The function of the unit is to disengage cruise control
if engine speed exceeds 5000 rev/min.

19FUEL SYSTEM
2
REPAIR ENGAGEMENT (ON/OFF) SWITCH
Service repair no - 19.75.30
Switch Replacement
Remove
1.Disconnect battery negative lead.
2.Carefully release auxiliary switch panel from
fascia.
3.Disconnect multiplug from switch.
4.Depress retaining lugs on switch, remove switch
from panel.
Bulb replacement
5.Position switch to facilitate removal of bulb.
6.Rotate bulb holder 90°and withdraw it from
switch.CRUISE CONTROL SWITCH
Service repair no - 19.75.36
Remove
1.Disconnect battery negative lead.
2. Models fitted with airbags:Remove driver's
airbag module.
See SUPPLEMENTARY
RESTRAINT SYSTEM, Repair, Driver's
Airbag Module
3. Models without airbags:Turn steering wheel
through 90°. Remove 2 Torx screws securing
pad to steering wheel and remove steering
wheel pad.
4.Disconnect cruise control switch multiplug from
main harness.

CRUISE CONTROL
3
REPAIR
5.Disconnect 2 Lucars from horn contacts.
6.Remove 2 screws securing cruise control switch
to steering wheel.
7.Remove 3 bolts securing mounting bracket to
steering wheel and remove mounting bracket.
8.Remove cruise control switch from steering
wheel.
Refit
9.Reverse removal procedure. Ensuring wiring
harness is routed correctly.
10. Models fitted with airbags:Refit driver's airbag
module and follow all safety precautions.
See
SUPPLEMENTARY RESTRAINT SYSTEM,
Repair, Driver's Airbag Module
ROTARY COUPLER
Service repair no - 19.75.54
The rotary coupler is located behind the steering
wheel. Access is gained by removing the steering
wheel and steering column shroud.
NOTE: On vehicles fitted with airbags.See
SUPPLEMENTARY RESTRAINT SYSTEM,
Repair, Rotary Coupler
Remove
1.Disconnect battery negative lead.
2.Remove steering wheel.
See STEERING,
Repair, Steering Wheel
3.Release 2 turnbuckles securing lower dash
closing panel and lower.
4.Remove 3 screws securing lower half of shroud
to steering column.
5.Disconnect rotary coupler multiplug from
steering column harness.

19FUEL SYSTEM
4
REPAIR
NOTE: If rotary coupler is to be re-used a
piece of adhesive tape should be placed
around the moulding in position A to
prevent rotation. Failure to do this may result in
damage to the wires inside the coupler.
6.Release clips securing rotary coupler to column
stalk assembly.
7.Remove rotary coupler from column stalk
assembly.
CAUTION: Ensure front wheels are in the
straight ahead position before removal
and refitting. Store in a plastic bag. DO
NOT rotate mechanism whilst removed.
Refit
8.Reverse removal procedure. Ensuring that the
column harnesses are not trapped by the
column shroud.
NOTE: If original rotary coupler is to be
fitted and there is evidence of tampering, it
is imperative that the coupler is
centralised.
See SUPPLEMENTARY RESTRAINT
SYSTEM, Repair, Rotary Coupler
NOTE: If a new rotary coupler is to be
fitted and the sealing tape is broken it
MUST NOT be used. Ensure rotary coupler
lugs are correctly engaged in the rear of the
steering wheel.ACTUATOR - V8i
Service repair no - 19.75.12
NOTE: The actuator is non serviceable, fit
a new unit if failure or damage occurs.
Remove
1.Disconnect battery negative lead.
2.Disconnect vacuum hose from actuator.
3.Remove nut securing actuator to throttle bracket.
4.Remove actuator, and manoeuvre actuator
operating link off throttle lever.
5.Withdraw actuator.
Refit
6.Inspect rubber diaphragm. Fit a new actuator
assembly if diaphragm is damaged.
7.Reverse removal procedure. Fitting the hook
uppermost.

19FUEL SYSTEM
6
REPAIR VACUUM PUMP - TDI
Service repair no - 19.75.06
NOTE: The vacuum pump is non
serviceable, fit a new unit if failure or
damage occurs.
Remove
1.Release turnbuckle securing wheel chock and
remove.
2.Release strap securing jack and remove.
3.Release 3 pump mounting rubbers from vehicle
body.
4.Manoeuvre pump out of box section.
5.Release multiplug cover and disconnect
multiplug from pump.
6.Disconnect vacuum hose from pump.
7.Remove pump.
Refit
8.Reverse removal procedure. Ensure all hose
and electrical connections are secure.

CLUTCH
1
DESCRIPTION AND OPERATION DESCRIPTION
The clutch unit fitted with the manual transmission,
comprises a single dry plate friction disc and
diaphragm spring clutch unit, secured to the engine
flywheel.OPERATION
The unit is operated hydraulically by the clutch master
cylinder 12 and a slave cylinder 13 attached to the
transmission bell housing.
1. Crankshaft and flywheel
2. Friction plate
3. Clutch cover
4. Diaphragm spring
5. Pressure plate
6. Fulcrum posts (9) for diaphragm spring
7. Bearing rings (2) for diaphragm spring
8. Retraction links and bolts (3) for pressure plate
9. Release bearing
10. Release lever11. Release lever pivot post
12. Master cylinder
13. Slave cylinder
14. Master cylinder pedal pushrod
15. Primary shaft and taper bearing (in gearbox)
16. Gearbox front cover
17. Primary shaft flywheel bush
18. Pedal pivot and return spring
19. Hydraulic damper (Diesel only)

33CLUTCH
2
DESCRIPTION AND OPERATION When the clutch pedal is depressed, hydraulic fluid
transmits the movement via the slave cylinder, release
lever 10, bearing 9, to the inner fingers of the
diaphragm spring 4.
The diaphragm spring 4 pivots on the bearing rings 7
and fulcrum posts 6 causing the pressure plate 5 to
release the clamping force on the friction plate and
linings 2.As the the clamping force is removed from the friction
plate 2, the plate slides on the splines of the primary
shaft 15 and takes up a neutral position between the
flywheel 1 and the pressure plate 5 , thus breaking the
drive between the engine and the gearbox.
NOTE: Diesel engined vehicles have an
hydraulic damper 19 fitted into the system.
The damper contains a steel diaphragm
which absorbs slight hydraulic pulses caused by
cyclic variations of the diesel engine crankshaft at
low rpm.

CLUTCH
1
FAULT DIAGNOSIS CLUTCH ASSEMBLY CONDITIONS
For the clutch to operate correctly as described and
illustrated in the "Description and Operation", it is
important the following conditions are satisfied:-
A. The primary shaft 15 must be free in the
crankshaft spigot bush 17.
B. The friction plate 2 must be able to slide easily
on the splines on the primary shaft 15, to a
position where it does not contact either the
flywheel or the pressure plate.
C. The friction plate must not be distorted or the
linings contaminated with oil, which may cause it
to stick or continue to run in contact with the
flywheel or pressure plate.
A number of faults can develop in the operation of the
clutch for a variety of reasons and although most
faults are due to normal wear at high mileage,
problems can also occur if the unit has been renewed
by an unskilled operator.
Recognising and diagnosing a particular clutch fault is
therefore of paramount importance in ensuring, that
the problem is rectified at the first attempt.
Problems which develop in the clutch are as follows:-
A. Clutch spin/drag
B. Clutch slip
C. Clutch judder/fierceCLUTCH SPIN - DRAG
Symptoms
Clutch spin is that, with engine running and clutch
pedal depressed, the gears cannot be immediately
engaged without making a grinding noise. This
indicates the clutch is not making a clean break.
However, if the clutch pedal is held depressed for
several seconds the friction plate will eventually break
free from the engine and the gear will engage silently.
Clutch spin as it becomes more severe develops into
clutch drag, making the silent engagement of a gear
impossible, regardless of how long the pedal is held
depressed.
CLUTCH SLIP
Symptoms
Clutch slip is most evident climbing a hill or when the
vehicle is moving off from stationary with a heavy
load. As the clutch is released slip occurs between the
engine and the transmission, allowing the engine
speed to increase without a corresponding increase in
vehicle speed.
Clutch slip can develop to the stage where no power
is transmitted through the clutch as the pedal is
released.
CLUTCH JUDDER - FIERCE
Symptoms
Clutch judder or fierce engagement, like slip, is most
likely to occur when the vehicle is moving off from
stationary. As the clutch pedal is released the vehicle
will move rapidly or in a series of jerks, which can not
be controlled even by careful operation of the clutch
by the driver.
It should be noted that a vehicle may display all the
symptoms or any combination of the symptoms
described, depending on the driving conditions vehicle
load and operating temperatures.

CLUTCH
1
REPAIR CLUTCH ASSEMBLY
Service repair no - 33.10.01
Clutch pressure plate
Renew pressure plate if diaphragm spring fingers are
worn or if pressure plate shows signs of wear, cracks
or burning.
Clutch driven plate
Renew driven plate if centre hub splines are worn or if
lining is contaminated, burned or unevenly worn.
Service tools:
Clutch centralising tool
LRT-12-001 - V8
LRT-12-040 - Tdi
LRT-12-057 - Mpi
Remove
1.Remove gearbox.
See MANUAL GEARBOX,
Repair, R380 Manual Gearbox
2.Mark position of clutch cover to flywheel for
reassembly.
3.Remove clutch cover securing bolts, working
evenly and diagonally.
4.Do not disturb three bolts in clutch cover.
5.Remove clutch assembly.
6.Withdraw clutch driven plate.
Refit
NOTE: To prevent clutch plate sticking,
lubricate splines using Rocol MV 3 or
Rocol MTS 1000 grease.
7.Renew/refit clutch driver plate and clutch
assembly using centralising tool, where
applicable, align assembly marks.
8.Secure clutch assembly cover fixings evenly,
working in a diagonal sequence. Tighten to
28
Nm.
9.Fit gearbox to engine.