Defender (1993+). Manual — part 95

AIR

CONDITIONING

7 .

The low side gauge should indicate a vacuum

Sweeping

of 660 mm Hg within five minutes.

8.

Whilst the system

is

evacuating, fill the

NOTE:

This operation

is

in addition

to

charging cylinder by opening the refrigerant

evacuating, and is to remove moisture from

drum valve.

systems that have been open

to

atmosphere for

9. Open the valve at the base of the charging

a

long

period,

or

that are known to contain

cylinder and fill the cylinder with 1,0 kg of

excessive moisture.

refrigerant. Liquid refrigerant will be observed
rising in the sight glass.

1.

Fit a new liquid receiver/drier, as detailed

open the valve at the top of the cylinder

2. Ensure that a full drum of refrigerant is fitted

(behind the control panel) intermittently, to

on the charging and testing equipment.

relieve the head pressure and allow the

3. Fit the charging and testing equipment as

refrigerant to continue filling the cylinder.

previously described for evacuating and

11.

When the refrigerant reaches the desired level

evacuate the air conditioning system, allowing

in the sight glass, close both the valve at the

0,25 to 0,45 kg of refrigerant

to

enter the

base of the cylinder and the valve at the

charging cylinder.

bottom of the refrigerant tank.

4. Close

all

valves on the charging and testing

12. Ensure the top cylinder valve is fully closed.

If

equipment.

bubbling is present in the sight glass, reopen

5. Disconnect the intake hose from the vacuum

equalise the drum and cylinder pressures.

13. If 660 mm Hg of vacuum is not achieved

within five minutes, it signifies either the

system has a leak

or

the vacuum pump is

defective. Initially check the vacuum pump, if
the pump proves

to

be functioning properly

then investigate for a leak in the air
conditioning system.

14.

Close the vacuum control valve No. 3.

15.

Stop the vacuum pump and allow the vacuum

to hold for fifteen minutes, then check that
there is no pressure rise (a

loss

of vacuum)

evident on the compound gauge. Any
pressure rise denotes a leak which must be
rectified before proceeding further. Refer

to

the heading titled ’Leak Detection’ later in this
section.

16. With the system satisfactorily evacuated, the

system is ready for charging with refrigerant.

10.

As the refrigerant stops filling the cylinder,

under the heading “Receiver/Drier”.

the cylinder base valve momentarily to

pump.

6. Connect the intake hose to the valve at the

top of the charging cylinder.

7 .

Open the valve at the top of the charging
cylinder.

8. Put on safety goggles.
9. Crack open the hose connection at valve

No.

3 and allow some refrigerant to purge the
hose, then close the connection.

10. Open the high pressure valve (No.2).
11.

Slowly open valve No. 3, which is now

connected to the top valve of the charging
cylinder, and allow gas

to

flow into the system

until the reading on the compound gauge
remains steady, Between 0,25 and 0,45 kg of
refrigerant will enter the system.

12. Allow the dry refrigerant introduced into the

system

to

remain for 10 minutes.

14

REISSUED: FEB

1993

AIR

CONDITIONING

13. Crack the suction valve charging line at the

6. If

the full charge

of

1,09

kg of liquid refrigerant

service port on the compressor to allow an

will not enter the system, then close the high

escape of refrigerant, at the same time

pressure valve (No.2) and open the low

observing the sight glass in the charging

pressure valve No.1), ensuring that the low

cylinder, A slight drop in the level should be
allowed before closing the connection at the

7.

Start and run the engine at 1,000 -1,500

compressor.

rev/min and allow refrigerant to be drawn

14. Close the high pressure valve (No.2).

though the low pressure valve (No. 1) until the

15.

Close valve No.3.

full charge has been drawn into the system.

16.

Close the valve at the top

of

the charging

8. Close valve No.1.

pressure gauge does not exceed 18.14 kgf².

cylinder.

9. Check the air conditioning system is operating

17. Reconnect

the

charging

and

testing

satisfactorily by carrying out

a

pressure test,

as described later in the Section

equipment, as described for evacuating and
evacuate the air conditioning system.

18. Maintain the vacuum for twenty minutes. The

CAUTION:

Do

not overcharge the air conditioning

air conditioning system is now ready for

system as this

will

cause excessive head

charging with refrigerant.

pressure.

Charging

Leak test

CAUTION:

Do

not charge liquid refrigerant into

the compressor. Liquid cannot

be

compressed;

and

if

liquid refrigerant enters the compressor

sensitive and widely used.

inlet valve, severe damage is possible; in
addition, the oil charge may

be

absorbed into the

1.

Place the vehicle in a well ventilated area but

refrigerant,

causing

damage

when

the

free from draughts, as leakage from the

compressor is operated.

system could be dissipated without detection.

2. Follow the

instructions issued by

the

1.

Fit the charging and testing equipment as

manufacturer of the particular leak detector

previously described for evacuating.

being used. Certain detectors have visual and

2. Evacuate the air conditioning system allowing

audible indicators.

1,09

kg of refrigerant to enter the charging

3. Commence searching for leaks by passing the

cylinder.

detector

probe

around

all

joints

and

3.

Put on safety goggles.

components, particularly on the underside, as

4. Close the low pressure valve (No.1).

the refrigerant gas is heavier than air.

5.

Open the refrigerant control valve (No. 4) and

4. Insert the probe into an air outlet of the

release liquid refrigerant into the system

evaporator. Switch the air conditioning blower

through the compressor discharge valve port

on and off at intervals of ten seconds.

Any

(High pressure). The pressure in the system

leaking refrigerant will be gathered in

by

the

will

eventually balance.

blower and detected.

The following instructions refer to an electronic type

refrigerant leak detector which is the safest, most

REISSUED:

FEB

1993

15

AIR

CONDITIONING

AIR

CONDITIONING

COMPRESSOR

COMPRESSOR DRIVE BELT

Remove

Adjust

1.

Site vehicle in a ventilated area.

1.

Slacken idler pulley securing bolt.

2. Disconnect the battery negative lead.
3. Discharge the air conditioning system, see

Discharging system

WARNING: Wear eye and hand protection when
disconnecting

components

containing

refrigerant.

Plug

all

exposed

connections

immediately.

4. Disconnect suction and discharge unions from

compressor.

5.

Disconnect electrical lead to compressor
clutch.

6.

Slacken idler pulley and release drive belt.

7.

Remove the two compressor mounting bolts
and lift compressor clear.

2. Adjust positron of idler pulley until correct

tension

is

obtained. The belt must be tight

with 4 to 6 mm total deflection when checked

by hand midway between pulleys on the
longest run.

3.

Tighten securing bolt and recheck tension.

CONDENSER FAN MOTORS

Removal

1.

Open and secure the bonnet.

2. Release the six self tapping screws securing

the front nose and grille assembly, lift clear.

3. Disconnect the electrical leads to the fans.

4. Remove the blanking caps

from

the fan

centres.

Refit

5. Remove the 8

mm

securing nuts, star and

spring washers

from

the fan blade centres,

pull blade from its respective fan motor shaft.

6. Release the

two

fan motor retaining bolts and

remove the motor whilst feeding the fan motor
through the appropriate aperture.

8.

If

a new compressor is being fitted, drain oil

from new compressor. Drain and measure oil
from old compressor. Add 30

ml

of new oil to

this amount and refill new compressor.

9.

Locate compressor in position, fit and tighten
mounting bolts.

10. Fit compressor drive belt, see Adjustment,

Compressor drive belt

11. Connect electrical lead to compressor clutch

at the connector.

12. Evacuate air conditioning system.

See

Evacuate system.

13. Charge

air

conditioning

system.

See

Charging system.

7.

Reverse procedures

1

to

6

ensuring the fan

supply wiring is routed and securely clipped
so that the wiring does

not

foul

the fan blades

REISSUED:

FEB 1993

17