Defender 90 NAS. Manual - part 90

AIR CONDITIONING

ADJUSTMENT

AIR CONDITIONING SYSTEM - PERFORMANCE
TEST

WARNING: R134a is hazardous

See

Repair, General Precautions .

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. Read both pressure gauges and thermometers.

Check readings against table below with
humidity between 60% and 80%.

7. Switch off air conditioning, stop engine,

disconnect test equipment.

Performance range

Intake temperature

Outlet temperature

Low pressure

High pressure

41 - 50

20 - 23 lbf/in

116 - 190 lbf/in

5 - 10

1.4 - 1.6 bar

8.0 - 13 bar

45 - 60

21 - 28 lbf/in

130 - 200 lbf/in

7 - 15

1.5 - 2.0 bar

9.0 - 14 bar

46 - 68

26 - 40 lbf/in

190 - 230 lbf/in

8 - 20

1.8 - 2.8 bar

13 - 16 bar

52 - 72

36 - 52 lbf/in

230 - 270 lbf/in

11 - 22

2.5 - 3.5 bar

16 - 19 bar

Table 1

Ambient

Compound Gauge

High Pressure

Temperature

Readings

Gauge Readings

bar

lbf/in

bar

lbf/in

1,3-1,4

15-20

6,9-10,3

100-150

1,4-1,7

20-25

9,7-13,1

140-190

100

1,7-2,1

25-30

12,4-15,5

180-225

110

2,1-2,4

30-35

14,8-17,2

215-250

AIR CONDITIONING

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 condenserate drain

tube is 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.

AIR CONDITIONING

REPAIR

COMPRESSOR

Service repair no - 82.10.20

Remove

1. Disconnect battery negative lead.
2. Recover refrigerant from system.

See

Adjustment, refrigerant recovery recycling
recharging

3. Remove 2 bolts securing hose flanges to

compressor.

WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed

connections immediately.

4. Disconnect high pressure pipe from compressor.
5. Disconnect low pressure pipe from compressor.
6. Remove ’O’ ring from each flange.
7. Disconnect multiplug from compressor clutch

fly-lead

8. Release drive belt from compressor pulley.

See

ELECTRICAL, Repair, Auxiliary drive belt

9. Remove 4 bolts securing compressor to

mounting bracket.

10. Remove compressor from mounting bracket.

Refit

11. New compressor: Drain oil from new compressor

outlet port. Drain and measure oil equal to
amount drained from old compressor, add 30 ml,
1 oz extra to this amount and refill new
compressor through outlet port.

12. Locate compressor in mounting bracket, fit bolts

and tighten to

25 Nm, 18 lbf ft.

13. Connect multiplug to fly-lead.
14. Fit NEW ’O’ rings to each pipe flange, lubricate

with refrigerant oil.

15. Engage pipe flanges, fit bolts and tighten to

Nm, 7 lbf ft.

16. Fit compressor drive belt.

See ELECTRICAL,

Repair, Auxiliary drive belt

17. Recharge refrigerant system.

See Adjustment,

refrigerant recovery recycling recharging

18. Reconnect battery negative lead.
19. Leak test disturbed joints.

See Adjustment,

leak test system

20. Carry out system test.

See Adjustment,

System test

CONDENSER FAN

Service repair no - 82.15.01

Remove

1. Remove grille panel.

See CHASSIS AND

BODY, Repair, grille panel

2. Disconnect multiplug from condenser fan

fly-lead.

3. Withdraw fly-lead from between radiator and

panel.

4. Remove nuts securing fan to condenser

brackets.

5. Remove fan assembly.

Refit

6. Position fan on brackets and secure with nuts.
7. Pass fly-lead through and connect to multiplug.
8. Fit grille panel.

See CHASSIS AND BODY,

Repair, grille panel

AIR CONDITIONING

REPAIR

CONDENSER

Service repair no - 82.15.07

Remove

1. Disconnect battery negative lead.
2. Recover refrigerant from system.

See

Adjustment, refrigerant recovery recycling
recharging

3. Remove condenser fan.

See condenser fan

4. Remove 4 bolts securing cross-braces to top

panel and chassis brackets.

5. Remove 2 cross-braces.
6. Using a backing spanner, loosen union nut

securing inlet pipe to condenser and disconnect.

7. Using a backing spanner, loosen union nut

securing outlet pipe to condenser and
disconnect.

8. Remove and discard ’O’ ring from each union.

CAUTION: Plug the connections.

WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant.

9. Remove 4 screws securing lower brackets to

condenser.

10. Remove 4 bolts securing brackets to top panel.
11. Release pipes and remove condenser assembly.

Do not carry out further dismantling if
component is removed for access only.

12. Transfer brackets to new condenser.

Refit

13. Fit NEW ’O’ rings to each union, lubricate with

refrigerant oil. New condenser, add 40 ml, 1 fl oz
refrigerant oil.

14. Add 40 ml, 1 fl oz of refrigerant oil to new

condenser.

15. Position condenser and engage pipes.
16. Secure brackets to top panel.
17. Secure lower brackets to condenser.
18. Using a backing spanner, tighten union nuts

securing pipes to condenser.

19. Fit condenser fan.

See condenser fan

20. Recharge refrigerant system.

See Adjustment,

refrigerant recovery recycling recharging

21. Reconnect battery negative lead.
22. Leak test disturbed joints.

See Adjustment,

leak test system

23. Carry out system test.

See Adjustment,

System test

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