1999 LAND ROVER DISCOVERY air condition

GENERAL INFORMATION
03-7
Ball and Roller Bearings
General
When removing and installing bearings, ensure that
the following practices are observed to ensure
component serviceability.
lRemove all traces of lubricant from bearing
under inspection by cleaning with a suitable
degreasant; maintain absolute cleanliness
throughout operations.
lConduct a visual inspection for markings on
rolling elements, raceways, outer surface of
outer rings or inner surface of inner rings. Reject
any bearings found to be marked, since marking
in these areas indicates onset of wear.
lHold inner race of bearing between finger and
thumb of one hand and spin outer race to check
that it revolves absolutely smoothly. Repeat,
holding outer race and spinning inner race.
lRotate outer ring gently with a reciprocating
motion, while holding inner ring; feel for any
check or obstruction to rotation. Reject bearing
if action is not perfectly smooth.
lLubricate bearing with generous amounts of
lubricant appropriate to installation.
lInspect shaft and bearing housing for
discoloration or other markings which indicate
movement between bearing and seatings.
lEnsure that shaft and housing are clean and
free from burrs before fitting bearing.
lIf one bearing of a pair shows an imperfection, it
is advisable to replace both with new bearings;
an exception could be if the faulty bearing had
covered a low mileage, and it can be
established that damage is confined to only one
bearing.
lNever refit a ball or roller bearing without first
ensuring that it is in a fully serviceable condition.
lWhen hub bearings are removed or displaced,
new bearings must be fitted; do not attempt to
refit the old hub bearings.lWhen fitting a bearing to a shaft, only apply
force to the inner ring of the bearing. When
fitting a bearing into a housing, only apply force
to the outer ring of the bearing.
lIn the case of grease lubricated bearings (e.g.
hub bearings) fill the space between bearing
and outer seal with the recommended grade of
grease before fitting seal.
lAlways mark components of separable bearings
(e.g. taper roller bearings) when dismantling, to
ensure correct reassembly. Never fit new rollers
in a used outer ring; always fit a complete new
bearing assembly.

GENERAL INFORMATION
03-17
Electrical Precautions
General
The following guidelines are intended to ensure the
safety of the operator while preventing damage to the
electrical and electronic components fitted to the
vehicle. Where necessary, specific precautions are
detailed in the individual procedures of this manual.
Equipment
Prior to commencing any test procedure on the
vehicle ensure that the relevant test equipment is
working correctly and any harness or connectors are
in good condition. It is particularly important to check
the condition of the lead and plugs of mains operated
equipment.
Polarity
Never reverse connect the vehicle battery and
always ensure the correct polarity when connecting
test equipment.
High voltage circuits
Whenever disconnecting live ht circuits always use
insulated pliers and never allow the open end of the
ht lead to contact other components, particularly
ECU's. Exercise caution when measuring the voltage
on the coil terminals while the engine is running, high
voltage spikes can occur on these terminals.Connectors and harnesses
The engine compartment of a vehicle is a particularly
hostile environment for electrical components and
connectors:
lAlways ensure electrically related items are dry
and oil free before disconnecting and
connecting test equipment.
lEnsure disconnected multiplugs and sensors
are protected from being contaminated with oil,
coolant or other solutions. Contamination could
impair performance or result in catastrophic
failure.
lNever force connectors apart using tools to
prise apart or by pulling on the wiring harness.
lAlways ensure locking tabs are disengaged
before disconnection, and match orientation to
enable correct reconnection.
lEnsure that any protection (covers, insulation
etc.) is replaced if disturbed.
Having confirmed a component to be faulty:
lSwitch off the ignition and disconnect the
battery.
lRemove the component and support the
disconnected harness.
lWhen replacing the component keep oily hands
away from electrical connection areas and push
connectors home until any locking tabs fully
engage.
Battery disconnection
Before disconnecting the battery, disable the alarm
system and switch off all electrical equipment. If the
radio is to be serviced, ensure the security code has
been deactivated.
CAUTION: To prevent damage to electrical
components, always disconnect the battery
when working on the vehicle's electrical system.
The ground lead must be disconnected first and
reconnected last.
CAUTION: Always ensure that battery leads are
routed correctly and are not close to any
potential chafing points.
Battery charging
Only recharge the battery with it removed from the
vehicle. Always ensure any battery charging area is
well ventilated and that every precaution is taken to
avoid naked flames and sparks.

GENERAL INFORMATION
03-18
Ignition system safety precautions
The vehicle's ignition system produces high voltage
and the following precautions should be observed
before carrying out any work on the system.
WARNING: Before commencing work on an
ignition system, ensure all high tension
terminals, adapters and diagnostic equipment
are adequately insulated and shielded to prevent
accidental personal contacts and minimise the
risk of shock. Wearers of surgically implanted
pacemaker devices should not be in close
proximity of ignition circuits or diagnostic
equipment.
Disciplines
Switch off the ignition prior to making any connection
or disconnection in the system to prevent electrical
surges caused by disconnecting 'live' connections
damaging electronic components.
Ensure hands and work surfaces are clean and free
of grease, swarf, etc. Grease collects dirt which can
cause electrical tracking (short-circuits) or high-
resistance contacts.
When handling printed circuit boards, treat with care
and hold by the edges only; note that some electronic
components are susceptible to body static.
Connectors should never be subjected to forced
removal or refit, especially inter-board connectors.
Damaged contacts can cause short-circuit and open-
circuit fault conditions.
Prior to commencing test, and periodically during a
test, touch a good vehicle body earth to discharge
static charge. Some electronic components are
vulnerable to the static electricity that may be
generated by the operator.
Grease for electrical connectors
Some under bonnet and under body connectors may
be protected against corrosion by the application of a
special grease during vehicle production. Should
connectors be disturbed in service, repaired or
replaced, additional grease should be applied: Part
No. BAU 5811, available in 150 gm tubs.
NOTE: The use of greases other than BAU 5811
must be avoided as they can migrate into relays,
switches etc. contaminating the contacts and leading
to intermittent operation or failure.
Supplementary Restraint System
Precautions
General
The Supplementary Restraint System (SRS)
provides active protection for vehicle occupants in
the event of a serious collision. The system
components include airbags and pretensioner seat
belts which are automatically deployed when a
severe frontal crash condition is detected.
In order to assure system integrity, it is essential that
the SRS system is regularly checked and maintained
so that it is ready for operation in the event of an
accident.
The SRS system contains components which could
be potentially hazardous to the service engineer if
not serviced and handled correctly. The following
guidelines are intended to alert the service engineer
to potential sources of danger and emphasise the
importance of ensuring integrity of the SRS
components fitted to the vehicle.
Where necessary, additional specific precautions are
detailed in the Restraint Systems section of this
Manual which should be referred to prior to
commencing repair operations.
It should be noted that these precautions are not
restricted to operations performed when servicing
the SRS system. The same care should be exercised
when working on ancillary systems and components
located in the vicinity of SRS components; these
include but are not limited to steering system (driver's
airbag), body and trim components (passenger's
airbag and seat belt pretensioners) and electrical
system components (SRS harnesses etc.).

GENERAL INFORMATION
03-19
WARNING: Do not use rear facing child seats in
the front passenger seat if the vehicle is fitted
with a passenger airbag.
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Replace the airbag every 10 years.
Do not install used SRS parts from another car.
When repairing an SRS system, always use
approved new parts.
Carefully inspect the airbag module before
installing it. Do not install an airbag module that
shows signs of being dropped or improperly
handled, such as dents, cracks or deformation.
Do not try to disassemble or tamper with the
airbag module.
Special bolts are necessary for installing the
airbag module. Do not use other bolts.
Preliminary procedures
The SRS system uses energy reserve capacitors
that keep the system active in the event of electrical
supply failure under crash conditions. It is necessary
to allow the capacitors sufficient time to discharge in
order to avoid the risk of accidental deployment.
Always remove the ignition key from the starter
switch, disconnect the vehicle battery and wait 10
minutes before commencing work on the SRS
system.
Carefully inspect any SRS component before
installation. Do not install any SRS component that
shows signs of damage such as dents, cracks or
deformity.Component handling
The SRS components are sensitive and potentially
hazardous if not handled correctly; always comply
with the following handling precautions:
lNever drop an SRS component. The airbag
Diagnostic Control Unit (DCU) is a particularly
shock sensitive device and must be handled
with extreme care. Airbag modules and seat belt
pretensioner units could deploy if subjected to a
strong shock.
lNever wrap your arms around an airbag
module. If an airbag module has to be carried,
hold it by the cover, with the cover uppermost
and the base away from your body.
lNever transport airbag modules or seat belt
pretensioners in the cabin of a vehicle. Always
use the luggage compartment of the vehicle for
carrying airbag modules and seat belt
pretensioner units.
WARNING: 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, before the unit
has been deployed.

GENERAL INFORMATION
03-23
Airbag and pretensioner deployment
Deployment procedures and precautions as detailed
in this manual should be strictly adhered to. Only
personnel who have undergone the appropriate
training should undertake deployment of airbag and
pretensioner modules. The following precautions
must be complied with:
lOnly use deployment equipment approved for
the intended purpose.
lBefore beginning deployment procedure,
ensure deployment tool functions properly by
performing the self test procedure detailed in
SRS section of this manual.
lDeployment of airbag/ pretensioner modules
should be performed in a well ventilated area
which has been designated for the purpose.
lEnsure airbag/pretensioner modules are not
damaged or ruptured before attempting to
deploy.
lNotify the relevant authorities of intention to
deploy airbag and pretensioner units.
lWhen deploying airbag pretensioner units,
ensure that all personnel are at least 15 metres
(45 feet) away from the deployment zone.
lEnsure deployment tool is connected correctly,
in compliance with the instructions detailed in
the SRS section of this manual. In particular,
ensure deployment tool is NOT connected to
battery supply before connecting to airbag
module connector.
lWhen deploying seat belt pretensioners, ensure
pretensioner unit is secured correctly to the
seat.
lWhen removing deployed airbag modules and
pretensioner units, wear protective clothing.
Use gloves and seal deployed units in a plastic
bag.
lFollowing deployment of any component of the
SRS system within the vehicle, all SRS
components must be replaced. DO NOT re-use
or salvage any parts of the SRS system.
lDo not lean over airbag module when
connecting deployment equipment.
If a vehicle is to be scrapped, undeployed airbag
modules and pretensioner units must be manually
deployed. In this case airbags can be deployed in the
vehicle; before deployment, ensure the airbag
module is secure within its correct mounting position.
Deployment of the driver's airbag in the vehicle may
damage the steering wheel; if the vehicle is not being
scrapped, deploy the module outside of the vehicle.
WARNING: During deployment parts of the
airbag module become hot enough to burn you.
Wait 30 minutes after deployment before
touching the airbag module.
SRS Component Replacement Policy
The following information details the policy for
replacement of SRS components; either as a result
of a vehicle accident or as a result of vehicle age.
Impacts which do not deploy the airbags or pre-
tensioners
Check for structural damage in the area of the
impact, paying particular attention to bumper
armatures, longitudinals, crash cans and bracketry.
Impacts which deploy the airbags or pre-
tensioners
The replacement and inspection policy is dependent
on the type and severity of of the crash condition.
The following guidelines are the minimum that
should be exercised as a result of the deployment of
specific SRS components.
If the front airbags or seat belt pre-tensioners are
deployed, the following parts must be replaced:
lSRS DCU.
lDriver airbag module
lPassenger airbag module
lFront seat belt buckle pre-tensioners
lRotary coupler
lDriver's seat belt retractor
lFlyleads (where applicable) connecting airbags
and seat belt pre-tensioners to SRS harness
In addition, the following should be inspected for
damage and replaced as necessary:
lFront passenger's seat belt retractor (webbing,
tongue latching, 'D' loop, body anchorage point)
lRear seat belt buckles (webbing, buckle covers,
body anchorage and tongue latching function)
lFascia moulding adjacent to passenger airbag
module
lSteering wheel (if damage is evident)
lFront seat frames and head restraints (if there is
evidence of damage to the seat frame or
cushion pan)
lSteering column (if adjustment is lost or there
are signs of collapse)
lThird row seats, seat belts and head restraints
(where fitted). Check third row seat latching
mechanism operates correctly.
Periodic replacement of SRS components
The performance of the propellants within airbags
and pre-tensioners will deteriorate over a period of
time. As a result, it is essential that the airbags are
replaced after 10 years and seat belt pre-tensioners
are replaced after 15 years in order to maintain
occupant safety.

GENERAL INFORMATION
03-24
Air Conditioning System Precautions
General
The air conditioning system contains fluids and
components which could be potentially hazardous to
the service engineer or the environment if not
serviced and handled correctly. The following
guidelines are intended to alert the service engineer
to potential sources of danger and emphasise the
importance of ensuring the integrity of the Air
Conditioning operating conditions and components
fitted to the vehicle.
Where necessary, additional specific precautions are
detailed in the relevant sections of this Manual which
should be referred to prior to commencing repair
operations.
The refrigerant used in the air conditioning system is
HFC-134a (Hydrofluorocarbon) R134a.
WARNING: Servicing must only be carried out by
personnel familiar with both the vehicle system
and the charging and testing equipment. All
operations must be carried out in a well
ventilated area away from open flame and heat
sources.
WARNING: R134a is a hazardous liquid and when
handled incorrectly can cause serious injury.
Suitable protective clothing, consisting of face
protection, heat proof gloves, rubber boots and
rubber apron or waterproof overalls, must be
worn when carrying out operations on the air
conditioning system.Remedial actions
If an accident involving R134a should occur, conduct
the following remedial actions:
lIf liquid R134a enters the eye, do not rub it.
Gently run large quantities of eye wash over
affected eye to raise the temperature. If an eye
wash is not available, cool, clean water may be
used to flush the eye. After rinsing, cover the
eye with a clean pad and seek immediate
medical attention.
lIf liquid R134a is splashed onto the skin, run
large quantities of water over the affected area
to raise the temperature. Implement the same
action if the skin comes in contact with
discharging cylinders. Wrap the contaminated
body parts in blankets (or similar materials) and
seek immediate medical attention.
lIf the debilitating effects of inhalation of R134a
vapour is suspected, seek fresh air. If the
affected person is unconscious, move them
away from the contaminated area to fresh air
and apply artificial respiration and/or oxygen
and seek immediate medical attention.
WARNING: Due to its low evaporating
temperature, R134a must be handled with care.
R134a splashed on any part of the body will
cause immediate freezing of that area. Also,
refrigerant cylinders and replenishment trolleys
when discharging will freeze skin to them if
contact is made.

GENERAL INFORMATION
03-25
Service precautions
Observe the following precautions when handling
components used in the air conditioning system:
lAir conditioning units must not be lifted by their
hoses, pipes or capillary lines.
lHoses and lines must not be subjected to any
twist or stress; the efficiency of the system will
be impaired by kinks or restrictions. Ensure that
hoses are correctly positioned before tightening
couplings, and ensure that all clips and supports
are utilised.
lFlexible hoses should not be positioned close to
the exhaust manifold (less than 100mm) unless
protected by heat shielding.
lCompleted assemblies must be checked for
refrigeration lines touching metal panels. Any
direct contact of components and panels may
transmit noise and so must be eliminated.
lThe appropriate torque wrench must be used
when tightening refrigerant connections to the
stipulated value. An additional spanner must be
used to hold the union to prevent twisting of the
pipe when tightening connections.
lBefore connecting any hose or pipe, ensure that
refrigerant oil is applied to the seat of the new 'O'
rings, BUT NOT to the threads of the
connection.
lAll protective plugs must remain in place to seal
the component until immediately prior to
connection.
lEnsure components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters it.
lComponents must not remain uncapped for
longer than 15 minutes. In the event of a delay,
the caps must be fitted.
lWhen disconnecting, immediately cap all air
conditioning pipes to prevent ingress of dirt and
moisture into the system.
lThe receiver/drier contains desiccant which
absorbs moisture. It must be positively sealed at
all times. A receiver/drier that has been left
uncapped must not be used, fit a new unit.
lThe receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection
of the system.
lWhenever the refrigerant system is opened, the
receiver/drier must be renewed immediately
before evacuating and recharging the system.
lUse alcohol and a clean lint-free cloth to clean
dirty connections.
lEnsure that all new parts fitted are marked for
use with R134a.
When a major repair has been completed, a leak test
should be conducted; refer to the Air Conditioning
section of this manual for the correct procedure.Refrigerant oil
Refrigerant oil easily absorbs water and must not
be stored for long periods. Do not pour unused
refrigerant oil back into the container. Always
use an approved refrigerant oil.

+ CAPACITIES, FLUIDS, LUBRICANTS
AND SEALANTS, Lubrication.
When replacing components in the A/C system,
drain the refrigerant oil from the component being
replaced into a graduated container. On assembly,
add the quantity of refrigerant oil drained to the new
component.
Compressor
A new compressor is sealed and pressurised with
Nitrogen gas. When fitting a new compressor, slowly
release the sealing cap; gas pressure should be
heard to vent as the seal is broken.
CAUTION: A new compressor should always be
sealed and could be pressurised with nitrogen
gas. To avoid possible oil loss, release the
sealing cap(s) slowly. Do not remove the cap(s)
until immediately prior to connecting the air
conditioning pipes to the compressor.
Rapid refrigerant discharge
If the air conditioning system is involved in accident
damage and the system is punctured, the refrigerant
will discharge rapidly. The rapid discharge 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 instructed in the air conditioning
section of this manual.

GENERAL INFORMATION
03-26
Precautions for refrigerant recovery, recycling
and recharging
When the air conditioning system is recharged, any
existing refrigerant is first recovered from the system
and recycled. The system is then charged with the
required weight of refrigerant and volume of
refrigerant oil.
WARNING: Refrigerant must always be recycled
before re-use to ensure that the purity of the
refrigerant is high enough for safe use in the air
conditioning system.
Recycling should always be carried out with
equipment which is design certified by
Underwriter Laboratory Inc. for compliance with
SAE J1991. Other equipment may not recycle
refrigerant to the required level of purity.
A R134a Refrigerant Recovery Recycling
Recharging Station must not be used with any
other type of refrigerant.
Refrigerant R134a from domestic and
commercial sources must not be used in motor
vehicle air conditioning systems.
CAUTION: The system must be evacuated
immediately before recharging commences.
Delay between evacuation and recharging is not
permitted.
Air Conditioning Compressor
Replacement
A new compressor is supplied filled with a full charge
(X cm3) of refrigerant oil.

+ CAPACITIES, FLUIDS, LUBRICANTS
AND SEALANTS, Capacities.A calculated quantity
of oil must be drained from the new compressor
before fitting. To calculate the quantity of oil to be
drained:
1Remove the drain plug from the old
compressor.
2Invert the compressor and gravity drain the oil
into a calibrated measuring cylinder. Rotate the
compressor clutch to ensure the compressor is
completely drained.
3Note the quantity of oil drained (Y cm
3).
4Calculate the quantity of oil to be drained from
the new compressor using the following
formula:
X cm
3 — (Y cm3 + 20 cm3) = Q cm3
5Remove the drain plug from the new
compressor and drain Q cm3 of oil. Fit and
tighten the compressor drain plug.