Subaru Impreza 2003, Service Manual

Page: 2733 / 3610

AC-15
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
GENERAL DESCRIPTION
C: CAUTION
1. HFC-134A A/C SYSTEM
• Unlike the old conventional CFC-12 system com-
ponents, the cooling system components for the
HFC-134a system such as the refrigerant and com-
pressor oil are incompatible.
• Vehicles with the HFC-134a system can be iden-
tified by the label “A” attached to the vehicle.
Before maintenance, check which A/C system is in-
stalled in the vehicle.
2. COMPRESSOR OIL
• HFC-134a compressor oil has no compatibility
with that for R12 system.
• Use only the manufacturer-authorized compres-
sor oil for the HFC-134a system; only use DH-PR.
• Do not mix multiple compressor oils.
If CFC-12 compressor oil is used in a HFC-134a
A/C system, the compressor may become stuck
due to poor lubrication, or the refrigerant may leak
due to swelling of rubber parts.
On the other hand, if HFC-134a compressor oil is
used in a CFC-12 A/C system, the durability of the
A/C system will be lowered.
• HFC-134a compressor oil is very hygroscopic.
When replacing or installing/removing A/C parts,
immediately isolate the oil from the atmosphere us-
ing a plug or tape. In order to avoid moisture, store
the oil in a container with its cap tightly closed.
3. REFRIGERANT
• The CFC-12 refrigerant cannot be used in the
HFC-134a A/C system. The HFC-134a refrigerant,
also, cannot be used in the CFC-12 A/C system.
• If an incorrect or no refrigerant is used, poor lu-
brication will result and the compressor itself may
be damaged.
4. HANDLING OF REFRIGERANT
• The refrigerant boils at approx.
−
30
°
C (
−
22
°
F).
When handling it, be sure to wear safety goggles
and protective gloves. Direct contact of the refriger-
ant with skin may cause frostbite.
If the refrigerant gets into your eye, avoid rubbing
your eyes with your hands. Wash your eye with
plenty of water, and receive medical treatment from
an eye doctor.
• Do not heat a service can. If a service can is di-
rectly heated, or put into boiling water, the inside
pressure will become extremely high. This may
cause the can to explode. If a service can must be
warmed up, use hot water in 40
°
C (104
°
F) max.
• Do not drop or impact a service can. (Observe
the precautions and operation procedure described
on the refrigerant can.)
• When the engine is running, do not open the
high-pressure valve of the manifold gauge. The
high-pressure gas will back-flow resulting in an ex-
plosion of the can.
• Provide good ventilation and do not work in a
closed area.
• In order to prevent global warning, avoid releas-
ing HFC-134a into the atmosphere. Using a refrig-
erant recovery system, discharge and reuse it.
AC-00006
(A)
(A) Goggles
(B) Gloves
(C) Avoid open flame
(D) No direct heat on container
(E) Do not discharge
(F) Loosen
(A)
(B)
(C) (D)
(E)
(F)
AC-00007