Subaru XT 1988 Service Manual page 1038

4-7
AIR CONDITIONING SYSTEM
5) When refrigerant can is empty, fully close both valves of
manifold gauge and replace refrigerant can with a new one.
Before opening manifold gauge valve to charge refrigerant
from new can, be sure to purge air from inside charging hose.
6) Charge the specified amount of refrigerant into system by
weighing charged refrigerant with scale. Overcharging will
cause discharge pressure to rise.
Measure the amount of charged refrigerant with a scale.
Make a note of the amount charged from can.
A26"()39
Fig. 19
Refrigerant capacity
Unit· kg (lb)
Refrigerant
Minimum Maximum
R-12 0.74 (1.63)
0.79 (1.74)
The presence of bubbles in sight glass of receiver drier is an
unsuitable method of checking the amount of refrigerant
charged in system. The state of the bubbles in sight glass
should only be used for checking whether the amount of
charged refrigerant is small or not. The amount of charged
refrigerant can be correctly judged by means of discharge
pressure. Refer to "Refrigerant Level Check".
7) After the specified amount of refrigerant has been charged
into system, close manifold gauge valves. Then detach charging
hoses from service valves of system. Be sure to install valve cap
to service valve.
8) Confirm that there are no leaks in system by checking
with a leak detector.
Refer to "Checking for Leaks".
Conducting a performance test prior to removing manifold
gauge is a good service operation. Refer to "Performance
Test".
Oi I separator
The Oil Separator Kit is used to efficiently withdraw the oil
in the refrigeration system (that is, to separate oil and refriger·
ant). If an excessive quantity of oil is charged in the system, or
if the quantity of oil in the system is unknown, adjust the
quantity of oil in the system to specification, proceeding as
follows:
1) Discharge air conditioning system. (Refer to "Discharging
System".)
2) Using two special flexible hoses and double union in Oil
Separator Kit connect oil separator between compressor dis·
charge side and condenser, as shown.
3) Evacuate and charge system. (Refer to "Evacuating and
Charging System.")
4) Fully open all windows or all doors of car.
5) Operate compressor at engine idling with air conditioner
set for maximum cooling and high fan speed.
Never allow engine speed to exceed idling speed.
6) Observe oil separator oil level gauge. If rise of oil level has
stopped, immediately stop compressor operation. (This indi·
cates that oil has been withdrawn.)
a. Do not continue oil withdrawal operation more than 10
minutes.
b. In some cases, fluid refrigerant may be mixed with oil,
causing unusual rise of oil level. In such a case, stop com-
pressor operation after ten minutes of withdrawal operation.
7) Discharge system. (Refer to "Discharging System.")
16
8) Disconnect oil separator, two flexible hoses and double
union from system.
9) Connect refrigerant lines to original positions.
1 0) Disconnect low flexible hose from compressor suction
valve.
11) Add 120 ml (4.1 US fl
OZ,
4.2 Imp fl ozl of new com·
pressor oil from compressor suction valve.
After charging, rotate compressor clutch with hand 5 to 10
turns.
12) Connect low flexible hose to compressor suction valve.
Evacuate and charge system. (Refer to "Evacuating System
and Charging Refrigerant".)
13) Conduct leak test and performance test.
14) Gradually loosen drain cap of oil separator to release
residual pressu reo Remove cap and drain oil.
15) To prevent formation of rust and intrusion of moisture
or dust, perform the following before placing oil separator
kit into storage.
(1
I
Cap each opening of two flexible hoses and double
union securely.
(2) Cap oil separator, evacuate it from service valve, and
charge refrigerant.