Range Rover Classic. Manual — part 169
82
AIR 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
with R134a.
Refrigerant oil
Use the approved refrigerant lubricating oil:
Nippon Denso ND-OIL 8
Unipart R134a ND-OIL8
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
40 ml
. . . . . . . . . . . . . . .
Evaporator
80 ml
. . . . . . . . . . . . . . .
Pipe or hose
20 ml
. . . . . . . . . . . . . ...
Receiver/drier
20 ml
. . . . . . . . . . . . . .
Total quantity of refrigerant oil in system = 180 ml =
6.3 Fl oz
A 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 must
not be removed until immediately prior to
fitting.
Fitting a new compressor
A new compressor is supplied with an oil fill (X) of:
180 ml
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 + 20 ml) = 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 the following amount
of new refrigerant oil:
130 ml
3. Plug the inlet and outlet ports.
AIR CONDITIONING
3
ADJUSTMENT
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
Safety goggles and gloves
REFRIGERANT RECOVERY RECYCLING
RECHARGING
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
manufacturer’s instructions.
Recovery and recycling
1. High pressure servicing connection
2. Low pressure servicing connection
1. Connect a Refrigerant Station to the high and
low pressure servicing connections.
2. Operate the refrigerant recovery system
according to the manufacturer’s 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.
82
AIR CONDITIONING
4
ADJUSTMENT
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.
4. Operate the refrigerant evacuation system
according to the manufacturer’s instructions.
NOTE: If the vacuum reading is below
700mmHg 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 manufacturer’s instructions.
Refrigerant to charge system is 0.90kg
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
car 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
are 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.
3. Carry out leak test as above.
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
°
C
4 - 10
°
C
18 - 28 lbf/in
2
213 - 299 lbf/in
2
1.2 - 1.9 bar
14.7 - 20.6 bar
25 - 29
°
C
9 - 19
°
C
27 - 37 lbf/in
2
256 - 341 lbf/in
2
1.9 - 2.6 bar
17.6 - 23.5 bar
30 - 35
°
C
20 - 27
°
C
33 - 47 lbf/in
2
299 - 384 lbf/in
2
2.3 - 3.2 bar
20.6 - 26.5 bar
Table 1
Ambient
Compound Gauge
High Pressure
Temperature
Readings
Gauge Readings
°
C
°
F
bar
lbf/in
2
bar
lbf/in
2
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
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