Subaru XT 1988 Service Manual page 1033

AIR CONDITIONING SYSTEM
4-7
SERVICE PROCEDURE
On-Car Service
REFRIGERANT R-12
The refrigerant used in the air conditioner is generally called
"Refrigerant-12 {R-12)". No other refrigerant than the above
refrigerant should be used. This refrigerant is usually available
in
a
small can or a cylinder. In either case, it is liquefied
under high pressure in the container.
Refrigerant evaporates easily (has a low evaporation point)
and, moreover, since the latent heat of the refrigerant is large,
it can absorb a large amount of heat when evaporating. Ex-
treme care must be exercised when handling the refrigerant.
COMPRESSOR 01 L
The "SUN ISO 5GS" refrigeration lubrication should be used
to assure the successful compressor operation. Use of oils
other than recommended or mixing of the oil with other
oils would cause chemical reaction or lead to lowered viscosi-
ty
or
deficient lubrication.
The oil absorbs moisture as it contacts the air. This points out
the need for care not to expose it to atmosphere for an ex-
tended period of time.
a. The oil should not be transfused from a container into
another, as the failure
will
possibly cause moisture to mix
with the oil.
b. The used oil should not be returned into a container.
c. The oil should not be used if its state of preselVation is not
clear enough.
MAINTENANCE
Periodical maintenance and season-in inspection
Both periodical maintenance and season-in inspection are
most essential to enable the air conditioner to give full per-
formance.
Perform the following checks.
1) Start engine and check refrigerant level through sight glass
on receiver drier. For details, refer to relative topics under
"Refrigerant Level Check".
2) Check the entire system for sign of refrigerant leaks.
Refer to relative topics under "Checking for Leaks" and
"Refrigerant Leaks".
If any trace of oil is noted at and around connection fittings,
it is a sure indication that refrigerant is .leaking. This con-
dition can be corrected easily by retightening the joints. If
any joint on line is suspected of small amount of leakage, use
a leak detector to locate leaking points.
3)
Check compressor drive belts for proper deflection.
Season-off
Observe the following maintenance tips to allow the air
11
conditioner to operate normally in the next season.
1 ) Keep the entire system free from refrigerant leakage by
periodically checking for refrigerant gas leak even out of
season.
2) Turn the compressor for 10 minutes at least once a month
by running the engine at 1 ,500 rpm.
GENERAL SERVICE INSTRUCTION
The servicing of the air conditioner should be carried out
only by well-trained servicemen. This chapter describes
essential points of servicing.
• If a large amount of dirt and sand ,enter the system, they
will be carried with refrigerant and may clog the system
or scratch rotating parts. This points out the need for
care in servicing the system. That is, disconnecting joints
should be carried out in a clean place.
• Water should not be allowed to get inside the system. The
refrigerant does not readily mix with water. However, the
presence of even a minute amount of water will cause a
chemical reaction at high temperature which will in turn
produce hydrochloric acid (HC1). Since hydrochloric acid
is highly corrosive to metals, the aluminum and copper
piping, etc. will become corroded and the refrigeration
system will become clogged.
• Water in the system will ice the orifice when the high
pressure refrigerant is changed to low pressure refrigerant
by expansion valve, etc., and will obstruct the refrigerant
flow.
SAFETY PRECAUTIONS
1) Since direct contact of the liquid refrigerant with your
skin will cause frostbite, always be careful when handling the
refrigerant. Wear gloves or wrap a piece of cloth around service
valve to protect your fingers against frostbite by refrigerant.
If any of the refrigerant should get into your eyes when
charging the refrigerant. splash your eyes with cool water to
raise the temperature gradually. Apply a protective film to
the eye to avoid infection. Do not rub your eyes. Consult
an eye special ist. Always wear goggles or glasses to protect
your eyes when working around the system. Should refrigerant
strike your body, splash on cool water and apply a protective
film.
2) The refrigerant service container has a safe strength. How-
ever, if\handled incorrectly, it will explode. Therefore, always
follow the instructions on the label. In particular, never
store it in a hot location [above 52°e (126°F)] or drop it
from a high height.
3)
The refrigerant gas is odorless and colorless and breathing
may become difficult due to the lack of oxygen. Since the
refrigerant gas is heavier than air and will lay close to the floor.
be especially careful when handling it in small, confined
spaces.
4) The refrigerant itself is nonflammable. However, a toxic