Land Rover Defender 90 Workshop 2nd Edition Nas Rover Manual

							HEATING AND VENTILATION
5
REPAIR HEATER CONTROL CABLE - AIR DISTRIBUTION
Service repair no - 80.10.12
Remove
1.Disconnect battery.
2.Remove steering wheel.
3.Remove steering column nacelle.
4.Remove instrument panel.
See
INSTRUMENTS, Repair, Instrument panel
5.Remove retaining screws and pull off air
distribution and temperature control lever knobs.
6.Remove 3 screws and detach side cover,
complete with control lever assembly.
7.Remove 2 screws securing control lever
assembly to side cover and remove cover.
Retain plastic screw spacers fitted between
cover and control lever assembly.
8.Remove bolt and release outer cable retaining
clip.
9.Slacken grub screw and release inner cable from
clevis.
10.Remove heater duct assembly.
See CHASSIS
AND BODY, Repair, Heater duct assembly
11.Remove 19 screws and lift off heater duct cover.
12.Slacken vent flap trunnion fixing, release air
distribution control cable and remove from
heater duct.
13.Check condition of foam sealant on heater duct
cover and renew if necessary.
Refit
14.Fit control cable through heater duct cover and
secure to vent flap trunnion. Bend over cable
end to fully secure.
15.Fit heater duct cover.
16.Fit heater duct assembly to fascia bulkhead.
See CHASSIS AND BODY, Repair, Heater
duct assembly
17.Route control cable along fascia bulkhead to
contol lever assembly.
18.With control lever in closed position, secure
cable to clevis.
19.Fit outer cable retaining clip to lever assembly.
20.Fit lever assembly to side cover. Ensure screw
spacers are fitted between cover and lever
assembly.
21.Fit side cover to fascia cowl.
22.Fit control lever knobs.
23.Fit instrument panel.
See INSTRUMENTS,
Repair, Instrument panel
24.Fit steering column nacelle. 
						

							80HEATING AND VENTILATION
6
REPAIR CONTROL CABLE AND BLOWER MOTOR SWITCH
Service repair no - 80.10.17 - Control cable
Service repair no - 80.10.22 - Blower motor switch
Remove
1.Disconnect battery.
2.From inside engine compartment, release outer
cable retaining clip at heater unit.
3.Slacken trunnion fixing and release inner cable
from heater unit flap lever.
4.Release 2 retaining clips securing control cables
to engine bulkhead and heater hoses.
5.Remove 4 screws securing instrument panel to
fascia cowl.
6.Pull instrument binnacle away from fascia to
ease access to control cable.
7.Remove 2 screws securing control lever
assembly to side of fascia binnacle cowl. Retain
plastic screw spacers fitted between cowl and
lever assembly.
8.Release lever assembly and disconnect 3
blower motor leads, noting their positions.
9.Pull control cable through bulkhead grommet
and out from instrument binnacle cowl.
10.Release retaining clip securing outer cable to
lever assembly.
11.Release inner cable from lever peg.
NOTE: Renew complete lever assembly if
the blower motor switch is faulty.
Refit
12.Fit control cable to lever assembly peg.
13.Fit retaining clip to secure outer cable.
14.Reconnect blower motor leads.
15.Route cable to rear of instrument panel cowl,
along bulkhead and out through grommet into
engine compartment.
16.Fit lever assembly to instrument panel cowl.
Ensure screw spacers are fitted between cowl
and lever assembly.
17.Fit instrument binnacle to fascia cowl.
18.With lever in closed position, fit control cable to
heater unit flap lever trunnion.
19.Secure outer cable with retaining clip.
20.Secure control cables to engine bulkhead and
heater hoses with retaining clips.
21.Reconnect battery. 
						

							AIR CONDITIONING
1
DESCRIPTION AND OPERATION SCHEMATIC LAYOUT OF THE AIR CONDITIONING
SYSTEM
1.Compressor
2.Condenser
3.Receiver/drier
4.Thermostatic expansion valve
5.Evaporator
6.Capillary tube
7.Trinary pressure switch
8.Condenser cooling fan - single only
9.Compressor high pressure relief valve
10.Sight glass - refrigerant
11.Drying agent - receiver/drier
12.Blower motorA1 Ambient air flow through condenser
A2 Recirclatory air flow through fan and evaporator
A3 Cooled air flow to vehicle interior
F1 High pressure high temperature refrigerant
vapour
F2 High pressure slightly subcooled refrigerant
liquid
F3 High pressure slightly subcooled refrigerant
liquid with moisture, vapour bubbles and foreign
matter removed
F4 Low pressure low temperature mixed liquid and
vapour
F5 Low pressure slightly super heated refrigerant
vapour 
						

							82AIR CONDITIONING
2
DESCRIPTION AND OPERATION AIR CONDITIONING SYSTEM OPERATION
The air conditioning system provides the means of
supplying cooled and dehumidified, recirculated air to
the interior of the vehicle. The cooling effect is
obtained by blowing air through the matrix of an
evaporator unit which has a variable temperature
control to provide the conditions required inside the
vehicle. The volume of cooled air supplied is
controlled by a variable speed blower.
A sealed system, charged with Refrigerant R134a,
together with a blower unit and evaporator
temperature control combine to achieve the cooled air
condition.
The air conditioning system comprises six major units:
1.An engine-mounted compressor.
2.A condenser mounted in front of the radiator.
3.A receiver/drier unit mounted on RH front
valance.
4.Thermostatic expansion valve mounted in front
of the evaporator.
5.An evaporator and blower unit mounted under
the RH side of the fascia panel.
6.Blower and temperature control switches.
These units are interconnected by hoses and pipes
carryingRefrigerant R134a,the evaporator is
seporate from the vehicle ventilation system.
Refrigeration cycle
1. Compressor
The compressor (1), belt driven from the crankshaft
pulley, is brought into operation by anACswitch on
the fascia which when selected engages an
electro-magnetic clutch to operate the compressor,
which pressurises and circulates the refrigerant
through the system. The electro-mechanical clutch
maintains the correct temperature and pressure by
engaging or disengaging to support the systems
requirements. The clutch action is normally controlled
by a thermostat located at the evaporator (5). The
compressor is of the swashplate type, having fixed
displacement.Should the temperature at the evaporator (5) fall low
enough for ice to begin to form on the fins, the
thermostat disengages the clutch and also isolates the
cooling fans relays. When the temperature at the
evaporator rises to the control temperature, the clutch
is re-engaged.
Should the system pressure become excessive or
drop sufficiently to cause damage to the compressor
(1) a trinary pressure switch (7), located in the high
pressure line, signals the relay unit to disengage the
clutch. The compressor also has an emergency high
pressure relief valve (9) fitted.
The condenser cooling fan operates continuously
when air conditioning is selected.
2. Condenser
From the compressor, hot high pressure vaporised
refrigerant (F1) passes to the condenser (2), which is
mounted in front of the engine coolant radiator. Ram
air (A1) passing through the condenser (2),
supplemented by the cooling fan (8) mounted in front
of the condenser, cools the refrigerant vapour
sufficiently to form a high pressure slightly subcooled
liquid (F2).
3. Receiver/drier
This liquid then passes to a receiver/drier (3) which
fulfils two functions. It acts as a reservoir and moisture
extractor (11).
A sight glass (10), in the high pressure line, provides a
method of determining the state of the refrigerant
without breaking into the system.
4. Expansion valve
From the receiver/drier (3) the moisture free high
pressure liquid refrigerant (F3) passes through a
thermostatic expansion valve (4). A severe pressure
drop occurs across the valve and as the refrigerant
enters the evaporator space at a temperature of
approximately -5°C, 23°F it boils and vaporises. 
						

							AIR CONDITIONING
3
DESCRIPTION AND OPERATION 5. Evaporator
As this change of state occurs, a large amount of
latent heat is absorbed. The evaporator is therefore
cooled and as a result heat is extracted from the air
flowing across the evaporator. The air flow is
controlled by the blower fans which can be operated
at various speeds.
To prevent liquid passing through to the compressor,
a capillary tube (6), attached to the outlet pipe of the
evaporator (5) and connected to the thermostatic
expansion valve (4), controls the amount that the
valve opens and closes in relation to the temperature
of the low pressure high temperature refrigerant
vapour (F4) at the outlet. The atomised refrigerant
then passes through the evaporator (5). Fan blown air
(A2) passes through the matrix (A3) of the evaporator
and is cooled by absorption due to the low
temperature refrigerant passing through the
evaporator.
A thermostat is positioned in the airflow leaving the
evaporator to sense the temperature of the exterior
fins. Should ice begin to form, due to a too cold
condition, it will signal to disengage the
electro-mechanical clutch on the compressor (1).
From the evaporator, low pressure, slightly
superheated refrigerant (F5) passes to the
compressor to complete the cycle.
AIR CONDITIONING CONTROL SYSTEM
The air conditioning control system comprises relays,
thermostat, pressure switches, and a control panel.
Together these controls, in conjunction with the
cooling fan, compressor clutch and blower, enable
minimal input to maintain the required environment
inside the vehicle.
Selecting air conditioning provides the added facility of
cooled air available to be mixed with warm air from
the heater system to give the required interior
environmental conditions.Trinary pressure switch
This switch, located in the high pressure line between
the receiver drier and the expansion valve, monitors
refrigerant pressure and by means of the relay
controls the following system functions:
1.Refrigerant pressure drops below 2.0 bar, 29
lbf/in
2(due to possible leakage), the
compressors electro-mechanical clutch is
dis-engaged.
2.When pressure rises above 2.0 bar, 29 lbf/in
2the
compressors clutch is re-engaged.
3.Refrigerant pressure rises above 32 bar, 455
lbf/in
2(due to possible blockage), even with
cooling fan operation, the compressors
electro-mechanical clutch is dis-engaged.
When the pressure drops below 26 bar, 375
lbf/in
2the compressor clutch is re-engaged.
Condenser cooling fan
The condenser cooling fan operates automatically
whenever the air conditioning system is switched on.
1. Blower control
The blower can be operated at various speeds by
turning the blower switch to the required position.
When the blower is switched off, the air conditioning
system will not operate.
2. Temperature control
Rotate the temperature control switch clockwise to
increase the cooling effect. Use in conjuction with the
blower control as required. 
						

							AIR CONDITIONING
1
FAULT DIAGNOSIS REFRIGERATION SYSTEM FAULTS
For any refrigeration system to function properly all
components must be in good working order. The unit
cooling cycle and the relationship between air
discharge temperature and ambient temperature and
the pressures at the compressor can help to
determine proper operation of the system.
The length of any cooling cycle is determined by such
factors as ambient temperature and humidity,
thermostat setting, compressor speed and air leakage
into the cooled area, etc. With these factors constant,
any sudden increase in the length of the cooling cycle
would be indicative of abnormal operation of the air
conditioner.
The low and high side pressures at the compressor
will vary with changing ambient temperature, humidity,
in-car temperature and altitude.
The following items should be checked before
operating the system:
1.Compressor drive belt tension.
2.Compressor magnetic clutch operation.
3.Condenser fan operation.
4.Condenser fins, dirt will cause poor cooling and
higher operating temperatures.System check
The following conditions should be checked after
operating the system for several minutes:
1.All high pressure lines and components should
be hot to the touch.
2.All low pressure lines should be cool to the
touch.
3.Inlet and outlet temperatures at the receiver/drier
should be at the same temperature (warm). Any
very noticeable temperature difference indicates
a blocked receiver/drier.
4.Heavy frost on the inlet to the expansion valve
may indicate a defective valve or moisture in the
system.
5.Evaporation air temperature will vary with
ambient temperature and humidity. As humidity
increases the outlet temperature will be higher. 
						

							AIR CONDITIONING
1
ADJUSTMENT GENERAL PRECAUTIONS
The refrigerant used in the air conditioning system is
HFC (Hydrofluorocarbon) R134a.
WARNING: R134a is a hazardous liquid
and when handled incorrectly can cause
serious injury. Suitable protective clothing
must be worn when carrying out servicing
operations on the air conditioning system.
WARNING: R134a is odourless and
colourless. Do not handle or discharge in
an enclosed area, or in any area where the
vapour or liquid can come in contact with naked
flame or hot metal. R134a is not flammable, but
can form a highly toxic gas.
WARNING: Do not smoke or weld in areas
where R134a is in use. Inhalation of
concentrations of the vapour can cause
dizziness, disorientation. uncoordination,
narcosis, nausea or vomiting.
WARNING: Do not allow fluids other than
R134a or compressor lubricant to enter the
air conditioning system. Spontaneous
combustion may occur.
WARNING: 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.
WARNING: The refrigerant used in an air
conditioning system must be reclaimed in
accordance with the recommendations
given with a Refrigerant Recovery Recycling
Recharging Station.
NOTE: Suitable protective clothing
comprises: Wrap around safety glasses or
helmet, heatproof gloves, rubber apron or
waterproof overalls and rubber boots.REMEDIAL ACTIONS
1.If liquid R134a strikes the eye, do not rub it.
Gently run large quantities of eyewash over the
eye to raise the temperature. If eyewash is not
available cool, clean water may be used. Cover
eye with clean pad and seek immediate medical
attention.
2.If liquid R134a is splashed on the skin run large
quantities of water over the area as soon as
possible to raise the temperature. Carry out the
same actions if skin comes into contact with
discharging cylinders. Wrap affected parts in
blankets or similar material and seek immediate
medical attention.
3.If suspected of being overcome by inhalation of
R134a vapour, seek fresh air. If unconscious,
remove to fresh air, apply artificial respiration
and/or oxygen and seek immediate medical
attention.
NOTE: Due to its low evaporating
temperature of -30°C, -22°F R134a should
be handled with care.
WARNING: Do not allow a refrigerant
container to be heated by a direct flame or
to be placed near any heating appliance. A
refrigerant container must not be heated above
50°C, 122°F.
WARNING: Do not leave a container of
refrigerant without its cap fitted. Do not
transport a container of refrigerant that is
unrestrained, especially in the boot of a car. 
						

							82AIR CONDITIONING
2
ADJUSTMENT SERVICING PRECAUTIONS
Care must be taken when handling refrigeration
system components. Units must not be lifted by their
hoses, pipes or capillary lines. Hoses and lines must
not be subjected to any twist or stress. Ensure that
hoses are positioned in their correct run before fully
tightening the couplings, and ensure that all clips and
supports are used. Torque wrenches of the correct
type must be used when tightening refrigerant
connections to the stated value. An additional spanner
must be used to hold the union to prevent twisting of
the pipe.
Before connecting any hose or pipe ensure that
refrigerant oil is applied to the seat of the new 0 ring
but not to the threads.
Check the oil trap for the amount of oil lost.
All protective plugs on components must be left in
place until immediately prior to connection.
The receiver/drier contains desiccant which absorbs
moisture. It must be positively sealed at all times.
CAUTION: Whenever the refrigerant
system is opened, the receiver/drier must
be renewed immediately before evacuating
and recharging the system.
Use alcohol and a clean cloth to clean dirty
connections. Ensure that all new parts fitted are
marked for use withR134a.
Refrigerant oil
Use the approved refrigerant lubricating oil - Nippon
Denso ND-OIL 8.
CAUTION: Do not use any other type of
refrigerant oil.
Refrigerant oil easily absorbs water and must not be
stored for long periods. Do not pour unused oil back
into the container.
When renewing system components, add the
following quantities of refrigerant oil:
Condenser 40ml, 1.4 fl oz............................................
Evaporator 80ml, 2.8 fl oz............................................
Pipe or hose 20ml, 0.7 fl oz..........................................
Receiver/drier 20ml, 0.7 fl oz........................................
Total refrigerant oil in system = 180ml, 6.3 fl ozA new compressor is sealed and pressurised with
Nitrogen gas. Slowly release the sealing cap, gas
pressure should be heard to release as the seal is
broken.
NOTE: A new compressor should always
have its sealing caps in place and these
must not be removed until immediately
prior to fitting
Fitting a new compressor
A new compressor is supplied with an oil fill (X) of
180ml, 5.3 fl oz.
A calculated quantity of oil must be drained from a
new compressor before fitting.
To calculate the quantity of oil to be drained:
1.Remove sealing plugs from the OLD
compressor.
2.Invert compressor and gravity drain oil into
measuring cylinder. Rotating the compressor
clutch plate will assist complete draining.
3.Note the quantity of oil drained (Y).
4.Calculate the quantity (Q) of oil to be drained
from the NEW compressor using the following
formula:
X - (Y + 20ml, 0.7 fl oz) = Q
Rapid refrigerant discharge
When the air conditioning system is involved in
accident damage and the circuit is punctured, the
refrigerant is discharged 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 follows:
1.Gravity drain all the oil, assist by rotating the
clutch plate (not the pulley).
2.Refill the compressor with 130ml, 4.6 fl oz of
new refrigerant oil.
3.Plug the inlet and outlet ports.
Servicing Equipment
The following equipment is required for full servicing
of the air conditioning system.
Recovery, recycling and charging station
- Leak detector
- Thermometer +20°C to -60°C, 70°F to -70°F
- Safety goggles and gloves 
						

							AIR CONDITIONING
3
ADJUSTMENT REFRIGERANT RECOVERY, RECYCLING,
RECHARGING
Service repair no - 82.30.20/01
WARNING: The air conditioning system is
charged with a high pressure, potentially
toxic refrigerant. Repairs or servicing must
only be carried out by an operator 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.
Always wear safety goggles and gloves when
opening refrigerant connections.
WARNING: Wear eye and hand safety
protection. Open connections slowly in
case liquid or pressure is present. Allow to
bleed off slowly.
CAUTION: Overcharging air conditioning
system will cause excessive head
pressure.
An air conditioning portable Refrigerant Recovery
Recycling Recharging Station for use with R134a
refrigerant incorporates all the features necessary to
recover refrigerant R134a from the air conditioning
system, to filter and remove moisture, to evacuate and
recharge with the reclaimed refrigerant. The unit can
also be used for performance testing and air
conditioning system analysis.
The operator must adhere to the equipment
manufacturers instructions.Recovery and recycling
1.Connect a Refrigerant Station to the high and
low pressure servicing connections.
2.Operate the refrigerant recovery system
according to the manufacturers instructions.
3.Measure the amount of oil discharged from the
system. Add an equal amount of new refrigerant
oil to compressor before evacuation sequence.
WARNING: Refrigerant must always be
recycled before reuse, 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.
Evacuation and recharging
1.Add refrigerant oil to compressor if necessary.
2.Renew the receiver/drier.
CAUTION: When a major repair has been
carried out, a leak test should be carried
out using inert gas.
3.Connect a Refrigerant Station to the high and
low pressure servicing connections.
CAUTION: Whenever the refrigerant
system is opened, the receiver/drier must
be renewed immediately before evacuating
and recharging the system. 
						

							82AIR CONDITIONING
4
ADJUSTMENT 4.Operate the refrigerant evacuation system
according to the manufactures instructions.
NOTE: If the vacuum reading is below 700
mm Hg, 28 in Hg after 15 minutes, suspect
a leak in the system. Partially recharge the
system and check for leaks using an electronic
leak tester. Check suction lines first, then run the
compressor for 5 minutes and then check the high
pressure lines.
CAUTION: The system must be Evacuated
immediately before recharging
commences. Delay between Evacuation
and Recharging is not permitted.
5.Operate the refrigerant recharging system
according to the manufacturers instructions.
Refrigerant to charge system = 900±30gm, 32
±1 oz.
6.If the full charge has not been accepted by the
system, start the engine and run it at 1500
rev/min for a minimum of 2 minutes.
Switch on the air conditioning system, open the
vehicle windows, set the temperature control to
cold and switch the blower to maximum speed.
7.Consult Refrigerant Station Manual for correct
procedure to complete the charge.
8.Carry out the air conditioning system
performance test.LEAK TEST SYSTEM
The following instructions refer to an electronic type
Refrigerant Leak Detector for use with R134a, which
is the safest and most sensitive.
CAUTION: When a major repair has been
carried out, a leak test should be carried
out using an inert gas (see below).
1.Place the vehicle in a well ventilated area but
free from draughts, as leakage from the system
could be dissipated without detection.
2.Follow the instructions issued by the
manufacturer of the particular leak detector
being used.
3.Commence searching for leaks by passing the
detector probe around all joints and components,
refrigerant gas is heavier than air.
4.Insert the probe into an air outlet of the
evaporator or into the evaporator drain tube.
Switch the air conditioning blower on and off at
intervals of ten seconds. Any leaking refrigerant
will be gathered in by the blower and detected.
5.Insert the probe between the magnetic clutch
and compressor to check the shaft seal for
leaks.
6.Check all service valve connections, valve plate,
head and base plate joints and back seal plate.
7.Check the condenser for leaks at the pipe
unions.
8.If any leaks are found, the system must be
discharged before rectification.
9.Rectify any leaks and recheck for leaks during
evacuation prior to charging.
Leak test using inert gas
Use Nitrogen or Helium gas.
1.Connect gas line to recharging station.
2.Pressurise system to 3 bar, 45 lbf/in
2.
3.Carry out leak test as above.