warning LAND ROVER DISCOVERY 1995 Workshop Manual

AIR CONDITIONING
5
ADJUSTMENT AIR CONDITIONING SYSTEM - PERFORMANCE
TEST
WARNING: R134a is hazardous, refer to
the GENERAL PRECAUTIONS given at the
beginning of this section.
Carry out this test with bonnet and doors or windows
open, air conditioning switched on, temperature
control set to cold and blower at maximum speed. Set
the air supply control to supply fresh air.
1.Close low pressure valve on refrigerant station.
2.Close high pressure valve on refrigerant station.
3.Connect a Refrigerant Station to the high and
low pressure servicing connections.4.Insert dry bulb thermometer into cold air outlet
and position dry and wet bulb thermometer close
to outside air inlet.
Do not spill water from the wet thermometer
(psychrometer).
5.Start engine and run it at 1500 rev/min for 10
minutes with air conditioning switched on.
6.Check that sight glass is free of bubbles.
7.Read both pressure gauges and thermometers.
Check readings against table below with
humidity between 60% and 80%. If readings are
incorrect.
See Fault diagnosis, Refrigeration
System Faults.
8.Switch off air conditioning, stop engine,
disconnect test equipment.
Performance range
Intake temperature Outlet temperature Low pressure High pressure
20 - 24°C4-10°C 18 - 28 lbf/in
2213 - 299 lbf/in2
1.2 - 1.9 bar 14.7 - 20.6 bar
25 - 29°C9-19°C 27 - 37 lbf/in2256 - 341 lbf/in2
1.9 - 2.6 bar 17.6 - 23.5 bar
30 - 35°C20-27°C 33 - 47 lbf/in2299 - 384 lbf/in2
2.3 - 3.2 bar 20.6 - 26.5 bar
Table 1
Ambient Compound Gauge High Pressure
Temperature Readings Gauge Readings
ÊC°F bar lbf/in
2bar lbf/in2
16 60 1,03-1,4 15-20 6,9-10,3 100-150
26,7 80 1,4-1,72 20-25 9,6-13,1 140-190
38 100 1,72-2,1 25-30 12,4-15,5 180-225
43,5 110 2,1-2,4 30-35 14,8-17,2 215-250

AIR CONDITIONING
1
REPAIR 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 fifteen 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
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.
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.
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.

82AIR CONDITIONING
2
REPAIR 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 and Receiver/Drier
Examine the sight glass for bubbles with the system
operating. Check connections for leakage.
Evaporator
Examine the refrigeration connections at the unit. If
the system should develop a fault, or if erratic
operation is noticed,
See Fault diagnosis,
Refrigeration System Faults
RECEIVER DRIER
Service repair no - 82.17.01
Remove
CAUTION: If receiver/drier is to be refitted,
the ports must be blanked off immediately
on disconnection. Exposed life of unit is
only 15 minutes.
1.Disconnect battery negative lead.
2.Recover refrigerant from system.
See
Adjustment, Refrigerant Recovery Recycling
Recharging
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
3.Remove 3 screws from bonnet locking platform
and remove radiator grille.
Automatic gearbox
4.Remove 4 bolts securing transmission oil cooler
to body.

AIR CONDITIONING
3
REPAIR 5.Disconnect 2 pipe unions from oil cooler. Use a
second wrench to support hose adapter.
6.Remove transmission oil cooler. Seal
connections.
All models
7.Remove bolt securing receiver/drier clamp.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
8.Move receiver/drier just sufficiently to gain
access to pipe flange bolts without distorting the
pipes.
9.Remove bolt securing each pipe flange to
receiver/drier.
10.Disengage pipe flanges and withdraw
receiver/drier from mounting bracket.
11.Remove 'O' ring from each pipe flange.Refit
12.Fit new 'O' ring to each pipe flange, lubricate
with refrigerant oil.
13.Position receiver/drier in mounting bracket with
inlet and outlet connections correctly aligned.
14.Engage pipe flanges, fit bolts in turn and tighten.
15.Fit clamp bolt.
Automatic gearbox
16.Refit transmission oil cooler. Use a second
wrench to support pipe unions.
17.Check gearbox fluid level, top-up if necessary.
All models
18.Evacuate and recharge air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging
19.Perform a leak test on disturbed joints.
20.Carry out a functional check.

82AIR CONDITIONING
4
REPAIR AIR CONDITIONING SWITCH
Service repair no - 82.20.29
Remove
1.Remove fascia centre louvre vent panel.
See
CHASSIS AND BODY, Repair, Dash Panel
Central Louvre Panel
2.Disconnect multiplug from switch
3.From the rear, push switch out of panel.
Refit
4.Reverse removal procedure.DUAL PRESSURE SWITCH
Service repair no - 82.20.20
Remove
1.Disconnect battery negative lead.
2.Recover refrigerant from system.
See
Adjustment, Refrigerant Recovery Recycling
Recharging
3.Disconnect multiplug from switch.
4.Unscrew switch from adapter. Use a second
wrench to support adapter.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
5.Remove 'O' ring from switch.
Refit
6.Reverse removal procedure. Lubricate new 'O'
ring with refrigerant oil and fit to switch.
7.Screw switch into adapter and tighten to
11 Nm.
8.Evacuate and recharge air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging

AIR CONDITIONING
5
REPAIR COMPRESSOR
Service repair no - 82.10.20
Remove
1.Disconnect battery negative lead.
2.Recover refrigerant from air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging
3.Remove screws retaining centre panel to fan
cowl
4.Remove centre panel.
V8i engine illustrated
5.Remove 2 bolts securing hose flanges to
compressor.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.6.Disconnect high pressure hose from
compressor.
7.Disconnect low pressure hose from compressor.
8.Remove 'O' ring from each flange.
9.Disconnect electrical lead from compressor
clutch.
10.Release drive belt from compressor pulley.
See
ENGINE, Repair, Drive Belt
11.Remove 4 bolts securing compressor to
mounting bracket.
12.Remove compressor from mounting bracket.
Refit
13.New compressor to be fitted: Drain oil from new
compressor outlet port. Drain and measure oil
from old compressor. Measure new oil equal to
amount drained from old compressor, add 30 ml
extra to this amount and refill new compressor
through outlet port.
14.Locate compressor in mounting bracket, fit bolts.
Tighten to
25 Nm.
15.Connect electrical lead to compressor clutch.
16.Fit new 'O' rings to high and low pressure hose
flanges, lubricate with refrigerant oil.
17.Engage hose flanges, fit bolts. Tighten to
10
Nm.
18.Fit compressor drive belt.See ENGINE, Repair,
Drive Belt
19.Fit centre panel to fan cowl.
20.Evacuate and recharge air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging
21.Perform a leak test on disturbed joints.
22.Carry out a functional check.

82AIR CONDITIONING
6
REPAIR CONDENSER
Service repair no - 82.15.07
Remove
1.Disconnect battery negative lead.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
2.Recover refrigerant from system.
See
Adjustment, Refrigerant Recovery Recycling
Recharging
3.Remove front grille panel.
4.Remove battery.
See ELECTRICAL, Repair,
Battery
5.Remove radiator and oil coolers assembly.See
COOLING SYSTEM, Repair, Radiator
6.Disconnect high and low pressure pipes at
condenser unions.
7.Discard 'O' ring seal from each union.
8.Remove 2 bolts securing condenser to body.
9.Pull condenser into radiator area.
10.Disconnect multiplug from each fan lead.
11.Remove condenser assembly.
Do not carry out
further dismantling if component is removed
for access only.
Blank off inlet and outlet ports.

82AIR CONDITIONING
8
REPAIR HEATER AND COOLER UNIT
Service repair no - 86.25.21
WARNING: All work involving the service
and maintenance of air conditioning
requires special equipment, knowledge,
experience and a full awareness and adherence to
safety precautions.
Remove
1.Disconnect battery negative lead.
2.Drain engine coolant.
See COOLING SYSTEM,
Adjustment, Coolant
3.Recover refrigerant from air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging
4.Remove fascia panel assembly.See CHASSIS
AND BODY, Repair, Dash Panel Assembly
5.Release clips and disconnect coolant hoses
from heater pipes.
6.Remove securing bolt and disconnect low
pressure pipe from evaporator.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
7.Release 'P' clip retaining high and low pressure
pipes.
8.Remove securing bolt and disconnect high
pressure pipe from evaporator.
9.Discard 'O' ring seals.

AIR CONDITIONING
9
REPAIR
10.Disconnect multiplug connecting heater to
blower unit, remove 3 screws and remove
blower unit.
11.Remove 5 screws securing casing to bulkhead
and tunnel.
12.Remove 2 securing bolts and remove centre
console front mounting bracket.
13.Disconnect 2 drain tubes..
14.Ease heater and cooler unit from its location and
remove from vehicle.
Refit
15.Ease heater and cooler unit into position.
16.Fit retaining bolts finger tight. Tighten in
sequence, centre and top bolts and then the
bottom bolt.
17.Reverse removal procedure.
18.Use new 'O' rings and lubricate with refrigerant
oil.
19.Evacuate and recharge system.
See
Adjustment, Refrigerant Recovery Recycling
Recharging
20.Leak test any disturbed joints.See Adjustment,
Leak Test System
21.Perform a functional check.EVAPORATOR AND EXPANSION VALVE
Service repair no - 86.25.20 - Evaporator
Service repair no - 86.25.01 - Expansion valve
Remove
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
1.Remove heater and cooler unit.
See Heater
and Cooler Unit

AIR CONDITIONING
11
REPAIR THERMOSTAT
Service repair no - 86.25.50
Remove
1.Remove heater and cooler unit.
See Heater
and Cooler Unit
2.Remove lower cover and evaporator.See
Evaporator and Expansion Valve
3.Remove 5 clips and screw securing evaporator
top cover.
4.Remove evaporator top cover.
5.Remove thermostat sensor from evaporator
matrix.
6.Remove 2 screws securing sensor unit.
7.Remove thermostat and insulation.
Refit
8.Reverse removal procedure.
CAUTION: The thermostat insulation must
be installed in the ORIGINAL POSITION in
the evaporator.EVAPORATOR/BLOWER MOTOR ASSEMBLY -
REAR
Service repair no - 82.26.01
Remove
1.Recover refrigerant from system.
See
Adjustment, refrigerant recovery recycling
recharging
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
2.Remove evaporator to alpine light duct.
See
evaporator to alpine light duct
3.Remove LH rear mud flap.See CHASSIS AND
BODY, Repair, mud flap - rear - lh
4.Clean area around low and high pressure air
conditioning pipe unions, beneath rear wheel
arch, to prevent any risk of dirt entering the
system.
5.Loosen and disconnect high and low pressure
air conditioning pipe unions beneath rear wheel
arch.
6.Remove and discard 'O' rings from pipe unions.
CAUTION: Use 2 spanners when loosening
or tightening air conditioning pipe unions.
CAUTION: Plug exposed connections
immediately.