LAND ROVER DEFENDER 1996 Workshop Manual

82AIR CONDITIONING
6
ADJUSTMENT SYSTEM TEST
1.Place the vehicle in a ventilated, shaded area
free from excessive draught, with the doors and
windows open.
2.Check that the surface of the condenser is not
restricted with dirt, leaves, flies, etc. Do not
neglect to check the surface between the
condenser and the radiator. Clean as necessary.
3.Switch on the ignition and the air conditioner air
flow control. Check that the blower is operating
efficiently at low, medium and high speeds.
Switch off the blower and the ignition.
4.Check that the evaporator condensate drain
tubes are open and clear.
5.Check the tension of the compressor driving belt,
and adjust if necessary.
6.Inspect all connections for the presence of
refrigerant oil. If oil is evident, check for leaks,
and repair as necessary.
NOTE: The compressor oil is soluble in
Refrigerant R134a and is deposited when
the refrigerant evaporates from a leak.
7.Start the engine.
8.Set the temperature controls to cold and switch
the air conditioner blower control on and off
several times, checking that the magnetic clutch
on the compressor engages and releases each
time.
9.With the temperature control at maximum
cooling and the blower control at high speed,
warm up the engine and fast idle at 1000
rev/min.
10.Repeat at 1800 rev/min.
11.Gradually increase the engine speed to the high
range and check the sight glass at intervals.
12.Check for frosting on the service valves.
13.Check the high pressure hoses and connections
by hand for varying temperature. Low
temperature indicates a restriction or blockage at
that point.
14.Switch off the air conditioning blower and stop
the engine.
15.If the air conditioning equipment is still not
satisfactory, carry out a pressure test as
previously described in this section.PRECAUTIONS IN HANDLING REFRIGERANT
LINES
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
1.When disconnecting any hose or pipe
connection the system must be discharged of all
pressure. Proceed cautiously, regardless of
gauge readings. Open connections slowly,
keeping hands and face well clear, so that no
injury occurs if there is liquid in the line. If
pressure is noticed, allow it to bleed off slowly.
2.Lines, flexible end connections and components
must be capped immediately they are opened to
prevent the entrance of moisture and dirt.
3.Any dirt or grease on fittings must be wiped off
with a clean alcohol dampened cloth. Do not use
chlorinated solvents such as trichloroethylene. If
dirt, grease or moisture cannot be removed from
inside the hoses, they must be replaced with
new hoses.
4.All replacement components and flexible end
connections must be sealed, and only opened
immediately prior to making the connection.
5.Ensure the components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters.
6.Components must not remain uncapped for
longer than 15 minutes. In the event of delay, the
caps must be fitted.
7.Receiver/driers must never be left uncapped as
they contain Silica Gel crystals which will absorb
moisture from the atmosphere. A receiver/ drier
left uncapped must not be used, fit a new unit.
8.The compressor shaft must not be rotated until
the system is entirely assembled and contains a
charge of refrigerant.
9.A new compressor contains an initial charge of
refrigerant oil. The compressor also contains a
holding charge of gas when received which
should be retained by leaving the seals in place
until the pipes are re-connected.
10.The receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection of
the system.

AIR CONDITIONING
7
ADJUSTMENT 11.All precautions must be taken to prevent
damage to fittings and connections. Slight
damage could cause a leak with the high
pressures used in the system.
12.Always use two wrenches of the correct size,
one on each fitting when releasing and
tightening refrigeration unions.
13.Joints and 'O' rings should be coated with
refrigeration oil to aid correct seating. Fittings
which are not lubricated with refrigerant oil are
almost certain to leak.
14.All lines must be free of kinks. The efficiency of
the system is reduced by a single kink or
restriction.
15.Flexible hoses should not be bent to a radius
less than 90mm radius.
16.Flexible hoses should not be within 100mm of
the exhaust manifold.
17.Completed assemblies must be checked for
refrigeration lines touching metal panels. Any
direct contact of lines and panels transmits noise
and must be eliminated.PERIODIC MAINTENANCE
Routine servicing, apart from visual checks, is not
necessary. The visual inspections are as follows:
Condenser
With a water hose or air line, clean the fins of the
condenser to remove flies, leaves, etc. Check the pipe
connections for signs of oil leakage.
Compressor
Check pipe connections for signs of oil leakage.
Check flexible hoses for swelling. Examine the
compressor belt for tightness and condition.
Sight glass
Examine the sight glass for bubbles with the system
operating. Check connections for leakage.
Evaporator
Examine the refrigeration connections at the unit.

AIR CONDITIONING
1
REPAIR COMPRESSOR
Service repair no - 82.10.20
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove compressor drive belt.See
Compressor drive belt
4.Disconnect high pressure pipe from compressor.
5.Disconnect low pressure pipe from compressor.
6.Remove 'O' ring from each flange.
7.Disconnect compressor clutch harness
multi-plug.
8.Remove compressor from mounting bracket
studs.Refit
9.If a new compressor is to be fitted first drain oil
from new compressor. Drain and measure oil
from old compressor. Measure new oil equal to
amount from old compressor, add 30 ml extra to
this amount and refill new compressor through
outlet port.
10.Locate compressor over mounting bracket studs.
11.Reconnect compressor clutch harness
multi-plug.
12.Fit new 'O' rings to high and low pressure hose
flanges, lubricate with refrigerant oil.
13.Fit high and low pressure hoses.
14.Fit compressor drive belt
See Compressor
drive belt.
15.Evacuate and recharge air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
16.Reconnect battery.
17.Perform a leak test on disturbed joints.
18.Carry out a functional check.

82AIR CONDITIONING
2
REPAIR COMPRESSOR DRIVE BELT
Service repair no - 82.10.02
Remove
1.Disconnect battery.
2.Remove auxiliary drive belt
See ELECTRICAL,
Repair, Auxiliary drive belt.
3.Remove 3 nuts securing drive belt guard to
compressor retaining studs.
4.Slacken 3 belt tensioner retaining bolts.
5.Remove compressor drive belt. Mark direction
on belt if refitting.Refit
6.Fit compressor drive belt.
7.Fit drive belt guard.
8.Fit torque meter to centre of tensioner, apply and
hold a torque of
35 Nm (26 lbf/ft).
9.Tighten tensioner retaining bolts.
10.Rotate crankshaft 2 full turns.
11.Reapply and hold a torque of
35 Nm (26 lbf/ft)
to tensioner, then fully slacken and retighten
tensioner retaining bolts to
25 Nm (18 lbf/ft).
12.Fit auxiliary drive beltSee ELECTRICAL,
Repair, Auxiliary drive belt.
13.Reconnect battery.

AIR CONDITIONING
3
REPAIR CONDENSER FAN AND MOTORS
Service repair no - 82.15.08
Remove
1.Disconnect battery.
2.Remove 6 screws and lift grille panel from
vehicle.
3.Disconnect fan motor multi-plugs and release
harness retaining clips.
4.Remove nut and washers and withdraw fan
blade from motor drive shaft.
5.Remove 2 retaining screws, release motor fan
from shroud support brackets and feed motor
multi-plug lead through appropriate aperture.
Refit
6.Feed motor lead through fan shroud.
7.Fit motor to fan shroud support brackets.
8.Reconnect fan lead multi-plug and secure with
retaining clips.
9.Fit fan blade to motor drive shaft.
10.Fit grille panel.
11.Reconnect battery.CONDENSER
Service repair no - 82.15.07
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove 6 screws and lift grille panel from
vehicle .
4.Disconnect condenser fan motor lead
multi-plugs.
5.Disconnect receiver/drier dual pressure switch
multi-plug.
6.Disconnect condenser low pressure pipe at
compressor.
7.Disconnect high pressure hose/pipe at
evaporator.

82AIR CONDITIONING
4
REPAIR
8.Remove 4 bolts and large packing washers
securing fan cowling brackets to wing sides.
9.Remove 4 nuts securing fan cowling to lower
mounting bracket and lift complete assembly
from condenser.
10.Remove 2 bolts securing bonnet striker support
plate and cross braces to grille top panel.
11.Remove 2 bolts securing cross braces to front
wings.
12.Lift condenser, from bottom mounting lugs and
carefully ease forwards to clear top grille panel.
13.Lift condenser, complete with receiver/drier, from
vehicle taking care to clear high and low
pressure hose/pipes at side of radiator.
14.Disconnect condenser and receiver/drier pipes.
15.Remove clamp bolts and release receiver/drier if
a new condenser is to be fitted.
16.Discard all pipe connection 'O' rings. Cap or plug
all connections to prevent ingress of dirt and
moisture.Refit
17.Coat unions, threads and new 'O' rings with
refrigerant oil prior to reassembly.
18.Secure receiver/drier to mounting clamps.
19.Fit condenser and receiver/drier pipes.
20.Lower condenser into position ensuring high and
low pressure pipes are located between radiator
and front wing.
21.Secure cross braces and bonnet striker support
plate to top grille.
22.Secure cross braces to front wings.
23.Secure fan cowl assembly to lower mounting
bracket and front wings.
24.Fit high pressure pipe at evaporator.
25.Fit condenser low pressure pipe at compressor.
26.Connect multi-plug at receiver/drier dual
pressure switch.
27.Connect fan motor lead multi-plug.
28.Evacuate and recharge air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
29.Reconnect battery.
30.Fit grille panel.

AIR CONDITIONING
5
REPAIR RECEIVER/DRIER
Service repair no - 82.17.01
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove 6 screws and lift grille panel from
vehicle.
4.Disconnect receiver/drier dual pressure switch
multi-plug.
5.Disconnect high pressure pipe at receiver/drier.
6.Disconnect bottom union at condenser.
7.Remove retaining bolts and open clamps.
8.Release receiver/drier from condenser and
discard. It is NOT recommended to refit old unit.
9.Discard all pipe connection 'O' rings. Cap or plug
all connections to prevent ingress of dirt and
moisture.
Refit
10.Coat unions, threads and new 'O' rings with
refrigerant oil prior to reassembly.
11.Secure new receiver/drier in retaining clamp.
12.Fit receiver/drier bottom union connector at
condenser.
13.Fit high pressure pipe to receiver/drier.
14.Fit pressure switch multi-plug.
15.Evacuate and recharge air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
16.Reconnect battery.
17.Fit grille panel assembly.HEATER/COOLER UNIT - LH DRIVE
Service repair no - 82.25.21
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove expansion tankSee COOLING
SYSTEM, Repair, Expansion tank
to gain
access to air conditioning high and low pressure
pipes.
4.Disconnect high and low pressure pipes. Discard
pipe connection 'O' rings. Cap or plug
connections to prevent ingress of dirt and
moisture.
5.Disconnect compressor clutch switch multi-plug.
6.Remove pipe connector from vacuum switch.
7.Remove retaining clip and disconnect control
cable from evaporator flap operating rod.
8.Remove screw and release outer cable retaining
bracket.

82AIR CONDITIONING
6
REPAIR 9.Remove plug connector from resistor.
10.Remove relay from connecting block to gain
access to fixing screw.
11.Remove screw and release relay connector
block. Retain relay in connector block.
12.Remove screw and detach air conditioning 30
amp fuse bracket from resistor. Refit both
resistor retaining screws.
13.Using suitable pipe clamps, clamp heater matrix
feed and return hoses at base of heater/cooler
unit. Release retaining clips and remove hoses.
14.From inside vehicle remove front passenger
carpet, if fitted.
15.Remove retaining screws and fold back footwell
insulation.
16.Remove 2 bolts securing heater/cooler unit lower
mounting bracket to bulkhead.
17.From inside engine compartment remove 2 bolts
securing top heater/cooler unit mounting bracket
to engine bulkhead. This also releases earthing
leads.
18.Remove bolt securing support bracket to front of
heater/cooler casing.19.Lift heater/cooler unit clear of air duct seal and
remove from vehicle.
20.Discard all pipe connection 'O' rings.
Refit
21.Coat unions, threads and new 'O' rings with
refrigerant oil prior to reassembly.
22.Position heater/cooler unit in engine
compartment and locate with air duct seal.
23.Secure unit top and bottom mounting brackets to
bulkhead and support bracket to front of unit
casing. Fully tighten fixing bolts when unit is
correctly positioned.
24.Fit footwell insulation.
25.Reconnect heater matrix hoses.
26.Fit air conditioning fuse bracket, relay connector
block, relay and resistor plug connector.
27.Fit control cable to evaporator air flap operating
rod, using a new clip.
28.Fit pipe connector to vacuum switch.
29.Connect compressor clutch switch multi-plug.
30.Connect high and low pressure pipes to
evaporator.
31.Fit expansion tank
See COOLING SYSTEM,
Repair, Expansion tank.
32.Evacuate and recharge air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
33.Reconnect battery.

AIR CONDITIONING
7
REPAIR EVAPORATOR - LH DRIVE
Service repair no - 82.25.20
Remove
1.Remove heater/cooler unit
See Heater/cooler
unit.
2.Suitably support unit on a bench to prevent
damage to heater matrix pipes.
3.Release 3 nuts and remove mounting bracket
from underneath unit casing.
4.Remove 7 screws securing outlet duct to
heater/cooler unit.
5.Carefully break sealing compound around edge
of duct and pull ducting from unit.
6.Remove 15 screws located around cover seam.
Break sealing compound from unit body and top
cover.
7.Remove 4 screws and 4 nuts from top of cover.
8.From front of unit remove 2 screws adjacent to
low pressure pipe moulding.
9.At side of unit remove 2 screws adjacent to air
intake aperture.
10.Lift off top cover, release grommet and feed
blower motor wiring and air control flap rod
through respective apertures. Note thermostat
temperature probe which is inserted in
evaporator matrix through top cover.
11.Lift support plate and insulation pad from heater
matrix.
12.From bottom of unit casing, remove 3 screws
adjacent to dump valve outlet, and screws next
to heater matrix pipes.

82AIR CONDITIONING
8
REPAIR
13.Remove all other fixings securing evaporator
and heater matrix support frame to unit casing.
14.Lift evaporator and heater matrices, complete
with support frame assembly, clear of casing.
Retain heater matrix pipe seal pad.
15.Remove 4 screws securing evaporator matrix to
support frame.
16.Withdraw evaporator matrix, complete with
expansion valve, from support frame.
17.Clean sealing compound from all joints of main
casing, top cover and outlet duct.
NOTE: The evaporator matrix is supplied
complete with the expansion valve.
However, a faulty expansion valve can be
serviced separately,
See Expansion valve.
Refit
18.Fit evaporator matrix in support frame.
19.Fit evaporator, heater matrix and support frame
assembly in casing. Ensure studs for lower
mounting bracket are located through bottom of
casing.
20.Apply mastic sealant around heater matrix pipes
to seal pipe apertures in casing. Fit seal pad
over pipes.
21.Fit 3 bottom fixings to secure to secure base of
support frame.
22.Fit all other fixings to secure support frame
assembly.
23.Locate heater matrix insulation pad and cover
plate.
24.Apply sealng compound around top edge of
main casing.
25.Feed blower motor wiring through top cover and
fit grommet.
26.Fit top cover to casing. Ensure thermostat
temperature probe is inserted in top of
evaporator. Apply mastic sealant to air flap
operating rod aperture.
27.Apply sealing compound to joint face of blower
motor outlet duct.
28.Locate duct over blower motor outlet and secure
to casing.
29.Secure lower mounting bracket to retaining studs
on base of main casing.
30.Fit heater/cooler unit assembly in engine
compartment
See Heater/cooler unit.