1999 LAND ROVER DISCOVERY service

FRONT SUSPENSION
REPAIRS 60-61
Actuator - front - ACE
$% 60.60.40
CAUTION: The ACE hydraulic system is
extremely sensitive to the ingress of dirt or
debris. The smallest amount could render the
system unserviceable. It is imperative that the
following precautions are taken.
lACE components are thoroughly cleaned
externally before work commences;
lall opened pipe and module ports are
capped immediately;
lall fluid is stored in and administered
through clean containers.
Remove
1.Raise vehicle on a ramp.
2.Remove RH front road wheel.
3.Position container to collect fluid spillage.
4.Remove cap nuts securing fluid pipes to
actuator. Disconnect pipes and discard sealing
washers.
CAUTION: Always fit plugs to open
connections to prevent contamination.5.Remove 2 nuts securing anti-roll bar links to
axle. Release links from axle.
6.With assistance, remove 2 bolts and remove
both clamp plates from torsion bar.
7.Remove mounting rubbers from torsion bar.
8.Remove torsion bar and actuator assembly.
CAUTION: While removed from the vehicle,
ensure torsion bar is stored without any
load on the anti-roll bar links, or the ball
joints and/or link rods could be damaged.

REAR SUSPENSION
64-14 DESCRIPTION AND OPERATION
The compressor is attached with Allen bolts to the motor housing and sealed with an O-ring. Attached to the
compressor is the air dryer which contains a silicate box for removing moisture from the compressed air. Air supplied
to inflate the air springs passes through the air dryer. When the air springs are deflated, the exhaust air also passes
through the air dryer, removing the moisture from the unit and expelling it to atmosphere.
Attached to end of the air dryer unit is the pressure limiting valve. The valve protects the air springs from over inflation.
The pressure limiting valve also operates when the exhaust valve is opened. The valve is pneumatically operated,
responding to air pressure applied to it.
The exhaust valve is also located with the pressure limiting valve. The exhaust valve is solenoid operated by the ECU
and directs air from the air springs and control valves to atmosphere when required.
The two air control valves for the LH and RH air springs are located at the forward end of the housing. Each valve is
connected to the compressor/air dryer unit through a shared single pipe which directs air to and from the air springs.
Each control valve is individually operated by the ECU.
All air connections to and from the air supply unit are made through the SLS air harness which is located along the
left hand chassis longitudinal.
If faults occur with the air supply unit, fault codes are stored in the SLABS ECU. These fault codes cover the
compressor power supply and the LH and RH air control valves and the exhaust valve. The current and past fault
codes can be retrieved with TestBook. TestBook can also be used to operate the compressor and the valves for
diagnostic purposes.
Air intake filter
The air intake filter is located in the left hand 'E' post, behind the tail lamp assembly. The filter comprises a plastic
moulded housing which contains two filters of differing density to remove particulate matter from the air drawn in by
the compressor. The air intake filter has a pipe which is connected to the SLS air harness by a quick release
connector. The air intake filter must be replaced as an assembly.
Air intake/Exhaust silencer
The air intake/exhaust silencer is located on the outside of the left hand chassis longitudinal, behind the air supply
unit. The silencer is an integral part of the SLS air harness and cannot be serviced individually.
The intake and exhaust air to and from the compressor passes through the silencer. The plastic moulded silencer has
two chambers. One chamber reduces system exhaust noise and the other dampens intake air pulses produced by
the compressor.

REAR SUSPENSION
REPAIRS 64-39
Actuator - rear - ACE
$% 64.60.40
CAUTION: The ACE hydraulic system is
extremely sensitive to the ingress of dirt or
debris. The smallest amount could render the
system unserviceable. It is imperative that the
following precautions are taken.
lACE components are thoroughly cleaned
externally before work commences;
lall opened pipe and module ports are
capped immediately;
lall fluid is stored in and administered
through clean containers.
Models with SLS:
WARNING: Ensure the air suspension system is
made safe before commencing work. Otherwise
the chassis may lower onto the bump stops
during repair.
Remove
1.Raise vehicle on ramp.
2.Remove nuts securing anti-roll bar links to
axle. Release links from axle.
3.Pull torsion bar down for access to actuator. 4.Remove nut securing anti-roll bar link to long
arm and remove link.
5.Position container to collect fluid spillage.
6.Remove cap nuts securing fluid pipes to
actuator. Disconnect pipes and remove and
discard sealing washers.
CAUTION: Always fit plugs to open
connections to prevent contamination.

REAR SUSPENSION
REPAIRS 64-41
Bushes - rear long arm - ACE
$% 64.60.46
CAUTION: The ACE hydraulic system is
extremely sensitive to the ingress of dirt or
debris. The smallest amount could render the
system unserviceable. It is imperative that the
following precautions are taken.
lACE components are thoroughly cleaned
externally before work commences;
lall opened pipe and module ports are
capped immediately;
lall fluid is stored in and administered
through clean containers.
Models with SLS:
WARNING: Ensure the air suspension system is
made safe before commencing work. Otherwise
the chassis may lower onto the bump stops
during repair.
Remove
1.Raise vehicle on ramp.
2.Remove nuts securing anti-roll bar links to axle.
Release links from axle.
3.Pull torsion bar down for access to actuator.4.Remove securing nuts and remove anti-roll bar
links from torsion bar.
5.Position container to collect fluid spillage.
6.Remove cap nuts securing fluid pipes to
actuator. Disconnect pipes and remove and
discard sealing washers.
CAUTION: Always fit plugs to open
connections to prevent contamination.
7.With assistance, remove bolts securing torsion
bar clamps. Remove clamps and remove
torsion bar and actuator.

RESTRAINT SYSTEMS
75-8 DESCRIPTION AND OPERATION
Diagnostic and Control Unit (DCU)
The SRS DCU is an electronic single point crash sensor. It is capable of sensing if a crash has taken place. If all the
relevant parameters are met, then the DCU deploys the airbag(s) and seat belt pretensioners.
The DCU is bolted to the transmission tunnel beneath the centre console in the area of the handbrake.
The DCU performs the following functions:
lInternal self test, system monitoring and fault detection.
lSRS warning lamp operation.
lSystem deployment.
Self test, system monitoring and fault detection
The DCU performs a self-test during start-up and then continually during operation of the system. The following
components are tested:
lThe decelerometer.
lThe electromechanical safing sensor.
lThe microprocessor.
lThe continuity of squib ignition circuits.
lThe SRS warning lamp.
If the DCU detects a fault, it stores the fault code in memory. Diagnose the DCU with TestBook. The DCU cannot
be serviced. It must be replaced if it is faulty.
SRS warning lamp operation
The DCU controls the SRS warning lamp contained in the instrument cluster.
System deployment
The DCU determines when the system deploys based on inputs from both the decelerometer and the
electromechanical safing sensor. Both are located within the DCU. Neither are serviceable.
The electromechanical safing sensor uses a magnet and ball bearing system to provide a mechanical confirmation of
vehicle deceleration. The ball bearing is held in place by the magnet. The strength of the magnet is calibrated such
that the force required for the ball bearing to move away from the magnet will only occur if the vehicle decelerates
suddenly, as in an accident.
The SRS deploys only if both the decelerometer reading and the safing sensor operation occur at the same time.

RESTRAINT SYSTEMS
75-24 REPAIRS
DCU
$% 76.74.06
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove centre console.
lOn manual gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
lOn automatic gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
3.Disconnect multiplug from DCU.
4.Remove 3 Torx bolts securing DCU to body and
remove DCU.
CAUTION: The SRS diagnostic control unit
is a non-serviceable component and no
attempt should be made to repair or modify
the unit.Refit
CAUTION: The SRS diagnostic control unit
is a shock sensitive device and must be
handled with extreme care.
1.Position DCU to body and connect multiplug.
2.Fit and tighten DCU Torx bolts to 10 Nm (7
lbf.ft).
3.Fit centre console.
lOn manual gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
lOn automatic gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
4.Connect battery leads, earth lead last.

SCREENS
76-4-4 REPAIRS
15.Apply a continuous bead of sealant to sealant
face on screen as shown.
16.With assistance, lift screen into place and align
to screen supports and tape. Ensure top
finisher is located into correct position. Lightly
press glass to fully seat sealer.
CAUTION: Do not apply heavy pressure to
the sides of the windscreen. Lightly press
windscreen from centre outwards until
edges are to required gap. Pushing sides
into position can bend windscreen and lead
to cracking in service.
17.Remove protective covers and tape.
18.Test sealer for leaks, apply additional sealer if
necessary. If water is used, allow sealer to dry
before testing. Spray water around glass and
check for leaks. Mark any area that leaks. Dry
glass and sealer then apply additional sealer.
19.Fit interior mirror to slug.
20.If applicable, connect screen heater multiplugs.
21.Fit air intake plenum.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
CAUTION: A curing time of 6 hours is
desirable. During this time leave a window
open to ventilate the vehicle interior. If the
vehicle must be used before the curing time
has elapsed, do not drive at speed or slam
the doors with the windows closed.
CAUTION: Vehicles fitted with a passenger
airbag should not be driven for 24 hours.
Glass - body side - rear
$% 76.81.18
Introduction
The following equipment is required:
lCutting wire and handles.
lKent cutting knife.
lGlazing knife.
lWindscreen repair kit.
lSealant applicator gun.
lSuction cups.
lA felt covered table or stand to support glass.
WARNING: Wear protective gloves when
handling glass, solvents and primers.
WARNING: Wear suitable eye protection when
removing and refitting glass.
Remove
1.If fitted, disconnect coaxial cable from terminal
on glass.
2.Fit protection to exterior body work adjacent to
glass.
3.Cover body panels adjacent to glass.
4.Fit protection to internal trim adjacent to glass.
5.Cover interior of vehicle with protective sheet.

SEATS
DESCRIPTION AND OPERATION 76-5-7
Lumbar pump
The lumbar pump inflates a bladder in the squab which provides extra support for the seat occupant. With no load on
the seat it takes approximately 10 seconds to completely inflate the bladder. With a load of 25 kg (55 lb) it takes
approximately 15 seconds to inflate the bladder. A pressure cut off switch in the system will operate at 0.12 to 1.93
bar (1.8 to 28 lbf.in
2). If a problem occurs with the lumbar bladder, e.g. a rupture, the whole lumbar system must be
replaced. The components are not serviceable.
Power comes from the seat switch pack through a 3A fuse in the satellite fuse box. The lumbar pump and the lumbar
deflate solenoid share an earth.
Lumbar deflate solenoid
The lumbar deflate solenoid vents the lumbar bladder to atmosphere to allow air to evacuate the bladder. The average
time to evacuate the bladder with a load of 25 kg (55 lb) is 9 seconds.
Power comes from the seat switch pack through a 3A fuse in the satellite fuse box. The lumbar deflate solenoid and
the lumbar pump share an earth.