air conditioning LAND ROVER DISCOVERY 1999 Workshop Manual

CONTENTS
CONTENTS 1
INTRODUCTION ...................................................................................... 01-1
How To Use This Manual................................................................................................................ 01-1
Repairs and Replacements ............................................................................................................. 01-2
Specifications .................................................................................................................................. 01-2
Abbreviations and Symbols ............................................................................................................ 01-3
GENERAL INFORMATION ...................................................................... 03-1
General Precautions ....................................................................................................................... 03-1
Safety Instructions .......................................................................................................................... 03-2
Environmental Precautions ............................................................................................................. 03-3
General Fitting Instructions ............................................................................................................. 03-6
Ball and Roller Bearings ................................................................................................................. 03-7
Oil Seals.......................................................................................................................................... 03-8
Joints and Joint Faces .................................................................................................................... 03-9
Locking Devices .............................................................................................................................. 03-9
Screw Threads ................................................................................................................................ 03-10
Bolt and Nut Identification ............................................................................................................... 03-11
Flexible Pipes and Hoses ............................................................................................................... 03-13
Rolling Road Testing....................................................................................................................... 03-15
Fuel Handling Precautions .............................................................................................................. 03-16
Electrical Precautions ..................................................................................................................... 03-17
Supplementary Restraint System Precautions ............................................................................... 03-18
SRS Component Replacement Policy ............................................................................................ 03-23
Air Conditioning System Precautions .............................................................................................. 03-24
Air Conditioning Compressor Replacement .................................................................................... 03-26
Body Repairs .................................................................................................................................. 03-27
GENERAL DATA ..................................................................................... 04-1
Engine - Td5 ................................................................................................................................... 04-1
Engine - V8 ..................................................................................................................................... 04-4
Fuel system - Td5 ........................................................................................................................... 04-8
Fuel system - V8 ............................................................................................................................. 04-8
Cooling system - Td5 ...................................................................................................................... 04-9
Cooling system - V8 ........................................................................................................................ 04-10
Clutch - Td5 .................................................................................................................................... 04-11
Clutch - V8 ...................................................................................................................................... 04-12
Manual gearbox - R380 .................................................................................................................. 04-13
Transfer box - LT230SE .................................................................................................................. 04-14
Automatic gearbox - ZF4HP22/24 .................................................................................................. 04-15
Rear axle......................................................................................................................................... 04-16
Front axle ........................................................................................................................................ 04-16
Steering........................................................................................................................................... 04-17
Suspension ..................................................................................................................................... 04-18
Brakes ............................................................................................................................................. 04-19
Wheels and tyres ............................................................................................................................ 04-20
Air conditioning ............................................................................................................................... 04-21
Electrical - Td5 ................................................................................................................................ 04-22
Electrical - V8 .................................................................................................................................. 04-22
Dimensions ..................................................................................................................................... 04-23
Weights ........................................................................................................................................... 04-24

CONTENTS
2CONTENTS
IDENTIFICATION NUMBERS .................................................................. 05-1
Vehicle Identification Number ......................................................................................................... 05-1
Identification Number Locations ..................................................................................................... 05-3
TORQUE WRENCH SETTINGS .............................................................. 06-1
Maintenance ................................................................................................................................... 06-1
Engine Td5 ..................................................................................................................................... 06-2
Engine V8 ....................................................................................................................................... 06-4
Emission control - Td5 .................................................................................................................... 06-5
Emission control - V8 ...................................................................................................................... 06-5
Engine management system - Td5 ................................................................................................. 06-6
Engine management system - V8................................................................................................... 06-6
Cooling system ............................................................................................................................... 06-7
Manifolds and exhaust systems - Td5 ............................................................................................ 06-8
Manifolds and exhaust systems - V8 .............................................................................................. 06-8
Clutch.............................................................................................................................................. 06-9
Manual gearbox - R380 .................................................................................................................. 06-10
Transfer box - LT230SE ................................................................................................................. 06-11
Automatic gearbox - ZF4HP22 ....................................................................................................... 06-12
Propeller shafts ............................................................................................................................... 06-13
Axles ............................................................................................................................................... 06-13
Steering .......................................................................................................................................... 06-14
Front suspension ............................................................................................................................ 06-15
Rear suspension ............................................................................................................................. 06-16
Brakes............................................................................................................................................. 06-17
Restraint systems ........................................................................................................................... 06-18
Body................................................................................................................................................ 06-19
Heating and air conditioning ........................................................................................................... 06-20
Wipers and washers ....................................................................................................................... 06-20
Electrical ......................................................................................................................................... 06-21
LIFTING AND TOWING ........................................................................... 08-1
LIFTING .......................................................................................................................................... 08-1
TOWING ......................................................................................................................................... 08-2
TRANSPORTING ........................................................................................................................... 08-4
CAPACITIES, FLUIDS, LUBRICANTS AND SEALANTS ...................... 09-1
Capacities ....................................................................................................................................... 09-1
Fluids .............................................................................................................................................. 09-2
Anti-Freeze Concentration .............................................................................................................. 09-2
Lubrication ...................................................................................................................................... 09-3
Sealants .......................................................................................................................................... 09-4

CONTENTS
CONTENTS 23
BODY SEALING MATERIALS ................................................................. 77-3-1
MATERIALS AND APPLICATIONS
Materials applications ..................................................................................................................... 77-3-1
Approved materials ......................................................................................................................... 77-3-2
Application equipment..................................................................................................................... 77-3-4
CORROSION PREVENTION AND SEALING .......................................... 77-4-1
CORROSION PREVENTION
Cavity wax treatment areas and injection holes - 'A' post and sill ................................................... 77-4-1
Cavity wax treatment area and injection hole - fuel filler neck ........................................................ 77-4-2
Cavity wax treatment areas and injection holes - rear cross member ............................................ 77-4-3
Cavity wax treatment areas and injection holes - front door, rear door and tail door ...................... 77-4-4
Corrosion prevention....................................................................................................................... 77-4-6
SEALING
Body Sealing ................................................................................................................................... 77-4-9
Water leaks ..................................................................................................................................... 77-4-22
PAINTING ................................................................................................ 77-5-1
PROCEDURES
Panel preparation............................................................................................................................ 77-5-1
Paint preparation............................................................................................................................. 77-5-2
HEATING AND VENTILATION................................................................. 80-1
DESCRIPTION AND OPERATION
Heating and ventilation component layout ...................................................................................... 80-1
Fuel burning heater component layout ........................................................................................... 80-2
Description ...................................................................................................................................... 80-3
Operation ........................................................................................................................................ 80-13
REPAIRS
Heater control and fan switch ....................................................................................................... 80-15
Cables - heater control .................................................................................................................. 80-15
Servo - recirculation flap ............................................................................................................... 80-17
Switch - recirculation control ......................................................................................................... 80-18
Servo - air distribution control ........................................................................................................ 80-19
Servo - air temperature control ....................................................................................................... 80-20
Plenum Air Intake ........................................................................................................................... 80-21
Heater assembly - models without air conditioning ......................................................................... 80-22
Heater assembly - models with air conditioning .............................................................................. 80-24
Blower assembly ............................................................................................................................ 80-26
Motor - blower ............................................................................................................................. 80-27
Resistor pack - power resistor A/C ............................................................................................... 80-28
Heater matrix ................................................................................................................................ 80-29
Pipe - Heater - Feed ...................................................................................................................... 80-29
Pipe - Heater - Return .................................................................................................................... 80-30
Fuel burning heater - (FBH) - Td5................................................................................................... 80-31

CONTENTS
24 CONTENTS
AIR CONDITIONING ................................................................................. 82-1
DESCRIPTION AND OPERATION
A/C refrigerant system component layout....................................................................................... 82-1
A/C control system component layout ............................................................................................ 82-2
Description ...................................................................................................................................... 82-3
Operation ........................................................................................................................................ 82-16
DESCRIPTION AND OPERATION
Rear A/C refrigerant system component layout .............................................................................. 82-21
Rear A/C distribution and control component layout ...................................................................... 82-22
Description ...................................................................................................................................... 82-23
Operation ........................................................................................................................................ 82-26
REFRIGERANT RECOVERY, RECYCLING AND RECHARGING
Refrigerant recovery, recycling and recharging .............................................................................. 82-27
REPAIRS
Compressor - diesel........................................................................................................................ 82-29
Compressor - V8............................................................................................................................. 82-30
Fan - condenser ............................................................................................................................ 82-31
Condenser .................................................................................................................................... 82-31
Receiver drier and dual pressure switch......................................................................................... 82-33
ECU - air temperature control ......................................................................................................... 82-35
Sensor - ambient air temperature ................................................................................................ 82-35
Sensor - solar light ........................................................................................................................ 82-36
Sensor - air temperature ............................................................................................................. 82-37
Evaporator, evaporator thermistor and thermal expansion valve (TXV) ........................................ 82-38
Expansion valve - (TXV) - rear ....................................................................................................... 82-41
Evaporator - rear............................................................................................................................. 82-42
Evaporator and motor assembly - rear ........................................................................................... 82-43
Blower motor assembly - rear ......................................................................................................... 82-44
Resistor - blower motor ................................................................................................................. 82-45
Duct - centre - rear.......................................................................................................................... 82-45

INTRODUCTION
01-3
Abbreviations and Symbols
A Amperes
AAP Ambient Air Pressure
ABDC After Bottom Dead Centre
ABS Anti-Lock Brake System
ac Alternating current
A/C Air Conditioning
ACE Active Cornering Enhancement
ACEA Association of Constructors of
European Automobiles
AFR Air Fuel Ratio
AP Ambient Pressure
ASC Anti-shunt Control
ATC Air Temperature Control
ATDC After Top Dead Centre
BBDC Before Bottom Dead Centre
BBUS Battery Backed Up Sounder
BCU Body Control Unit
BDC Bottom Dead Centre
bhp Brake Horse Power
BP Boost Pressure
BPP Brake Pedal Position
BS British Standard
BTDC Before Top Dead Centre
C Celsius
CAN Controller Area Network
CD Compact Disc
CDC Centre Differential Control
CDL Central Door Locking
CD - ROM Compact Disc - Read Only
Memory
CFC Chlorofluorocarbon
CHMSL Centre High Mounted Stop Lamp
CKP Crankshaft Position
CLV Calculated Load Value
cm Centimetre
cm
2Square centimetre
cm3Cubic centimetre
CMP Camshaft Position
CPP Clutch Pedal Position
CO Carbon Monoxide
CO
2Carbon Dioxide
CR Common Rail
CVS Canister Vent Solenoid
deg. Degree, angle or temperature
dia. Diameter
DIN Deutsche Industrie Normen
(German Industrial Standards)
dc Direct current
DCV Directional Control Valve
DOHC Double Overhead Camshaft
DTI Dial Test Indicator
DFM Dual Mass Flywheel
DVD Digital Versatile Disc
EACV Electronic Air Control Valve EAT Electronic Automatic
Transmission
EBD Electronic Brake pressure
Distribution
ECD European Community Directive
ECM Engine Control Module
ECT Engine Coolant Temperature
ECU Electronic Control Unit
EDC Electronic Diesel Control
EEPROM Electronic Erasable
Programmable Read Only
Memory
EGR Exhaust Gas Recirculation
EKA Emergency Key Access
EN European Norm
EOBD European On Board Diagnostics
ETC Electronic Traction Control
EUI Electronic Unit Injector
EVAP Evaporative Emission
EVR Electronic Vacuum Regulator
F Fahrenheit
FBH Fuel Burning Heater
FIP Fuel Injection Pump
FTC Fast Throttle Control
g Gramme or Gravity
hHour
hc High compression
HC Hydro Carbons
HDC Hill Descent Control
HDPE High Density Polyethylene
HFS Heated Front Screen
Hg Mercury
HO2S Heated Oxygen Sensor
HMW High Molecular Weight
HRW Heated Rear Window
ht/HT High tension
IACV Idle Air Control Valve
IAT Intake Air Temperature
ICE In-Car Entertainment
i.dia. Internal diameter
IDM Intelligent Driver Module
in3Cubic inch
ILT Inlet Throttle
ISO International Organisation for
Standardisation
k Thousand
kg Kilogramme
km Kilometre
km/h Kilometres per hour
kPa KiloPascal
KS Knock Sensor
lLitre
lbf.in Pounds force inches
lbf/in
2Pounds per square inch
lbf.ft Pounds force feet

GENERAL INFORMATION
03-3
Environmental Precautions
General
This section provides general information which can
help to reduce the environmental impacts from the
activities carried out in workshops.
Emissions to air
Many of the activities that are carried out in
workshops emit gases and fumes which contribute to
global warming, depletion of the ozone layer and/or
the formation of photochemical smog at ground
level. By considering how the workshop activities are
carried out, these gases and fumes can be
minimised, thus reducing the impact on the
environment.
Exhaust fumes
Running car engines is an essential part of workshop
activities and exhaust fumes need to be ventilated to
atmosphere. However, the amount of time engines
are running and the position of the vehicle should be
carefully considered at all times, to reduce the
release of poisonous gases and minimise the
inconvenience to people living nearby.
Solvents
Some of the cleaning agents used are solvent based
and will evaporate to atmosphere if used carelessly,
or if cans are left unsealed. All solvent containers
should be firmly closed when not needed and
solvent should be used sparingly. Suitable
alternative materials may be available to replace
some of the commonly used solvents. Similarly,
many paints are solvent based and the spray should
be minimised to reduce solvent emissions.
Refrigerant
It is illegal to release any refrigerants into the
atmosphere. Discharge and replacement of these
materials from air conditioning units should only be
carried out using the correct equipment.
Checklist
Always adhere to the following.
Engines:
ldon't leave engines running unnecessarily;
lminimise testing times and check where the
exhaust fumes are being blown.
Materials:
lkeep lids on containers of solvents;
lonly use the minimum quantity;
lconsider alternative materials;
lminimise over-spray when painting. Gases:
luse the correct equipment for collecting
refrigerants;
ldon't burn rubbish on site.
Discharges to water
Most sites will have two systems for discharging
water: storm drains and foul drains. Storm drains
should only receive clean water, foul drains will take
dirty water.
The foul drain will accept many of the normal waste
waters such as washing water, detergents and
domestic type wastes, but oil, petrol, solvent, acids,
hydraulic oil, antifreeze and other such substances
should never be poured down the drain. If in any
doubt speak to the Water Company first.
Every precaution must be taken to prevent spillage of
oil, fuel, solvents etc. reaching the drains. All
handling of such materials must take place well away
from the drains and preferably in an area with a kerb
or wall around it, to prevent discharge into the drain.
If a spillage occurs it should be soaked up
immediately. Having a spill kit available will make
this easier.
Additional precautions
Check whether the surface water drains are
connected to an oil water separator, this could
reduce the pollution if an incident was to occur. Oil
water separators do need regular maintenance to
ensure effectiveness.
Checklist
Always adhere to the following.
Disposal:
lnever pour anything down a drain without first
checking that it is environmentally safe to do so,
and that it does not contravene any local
regulations or bye-laws;
l have oil traps emptied regularly.
Spillage prevention:
lstore liquids in a walled area;
lmake sure that taps on liquid containers are
secure and cannot be accidentally turned on;
lprotect bulk storage tanks from vandalism by
locking the valves;
ltransfer liquids from one container to another in
an area away from open drains;
lensure lids are replaced securely on containers;
lhave spill kits available near to points of storage
and handling of liquids.

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.

GENERAL DATA
04-21
Air conditioning
Type CFC free, sealed closed loop
Compressor:
⇒ Displacement 177.7 cm
3/rev (10.84 in3/rev)
⇒ Relief valve operating pressure 34.3 to 41.4 bar (497 to 600 lbf.in
2)
⇒ Refrigerant oil quantity 180ml (6.3 fl.oz)
Dual pressure switch operating pressures (nominal):
⇒ Low pressure switch Opens 2.0 bar (29.0 lbf.in
2), pressure decreasing
⇒ Low pressure switch Closes 2.3 bar (33.4 lbf.in
2), pressure increasing
⇒ High pressure switch Opens 32 bar (464 lbf.in
2), pressure increasing
⇒ High pressure switch Closes 26 bar (377 lbf.in
2), pressure decreasing