Subaru Legacy III (2000-2003 year). Manual - part 857

AC-16

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

GENERAL DESCRIPTION

C: CAUTION

1. HFC-134A A/C SYSTEM

• Unlike the old conventional HFC-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
ZXL200PG for LHD model or DENSO OIL9 for
RHD model.
• Do not mix multiple compressor oils.
If HFC-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 HFC-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 HFC-12 refrigerant cannot be used in the
HFC-134a A/C system. The HFC-134a refrigerant,
also, cannot be used in the HFC-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.

−

C (

−

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.
• The refrigerant is non-toxic and harmless under
normal operating circumstance, but it may change
to phosgene (a noxious fume) under open flames
or high temperatures (caused by a cigarette or
heater).
• Provide good ventilation and do not work in a
closed area.
• Never perform a gas leak test using a halide
torch-type leak tester.

AC-00006

( A )

AC-17

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

GENERAL DESCRIPTION

• In order to avoid destroying the ozone layer, pre-
vent HFC-134a from being released into the atmo-
sphere. Using a refrigerant recovery system,
discharge and reuse it.

5. O-RING CONNECTIONS

• Use new O-rings.
• In order to keep the O-rings free of lint which will
cause a refrigerant gas leak, perform operations
without gloves and shop towels.
• Apply the compressor oil to the O-rings to avoid
sticking, then install them.
• Use a torque wrench to tighten the O-ring fittings:
Over-tightening will damage the O-ring and tube
end distortion.
• If the operation is interrupted before completing a
pipe connection, recap the tubes, components, and
fittings with a plug or tape to prevent contamination
from entering.

• Visually check the surfaces and mating surfaces
of O-rings, threads, and connecting points. If a fail-
ure is found, replace the applicable parts.
• Install the O-rings at right angle to the tube
beards.

(A) Goggle

(B) Gloves

(D) No direct heat on container

(E) Do not discharge

(F) Loosen

AC-00007

( A )

( B )

( C )

( D )

( E )

( F )

(A) Seal

(A) O-ring

(B) O.K.

(D) Bead

AC-00008

( A )

AC-00009

( A )

( B )

( C )

( D )

AC-18

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

GENERAL DESCRIPTION

• Use the oil specified in the service manual to lu-
bricate the O-rings.
Apply the oil to the top and sides of the O-rings be-
fore installation.
Apply the oil to the area including the O-rings and
tube beads.

• When connecting hoses or pipes, use 2 wrench-
es (a torque wrench for tightening). While securing
one side with a wrench, tighten the other side to the
specified torque with a torque wrench.
If only one wrench is used to tighten, the tightening
torque will be excessive or insufficient. This may
cause a pipe distortion or gas leak, resulting in
damage to hoses and pipes.
• After tightening, using a clean shop towel to re-
move excess oil from the connections and any oil
which may have run on the vehicle body or other
parts.

• If any leakage is suspected after tightening, do
not retighten the connections, Disconnect the con-
nections, remove the O-rings, and check the O-
rings, threads, and connections.

(A) Apply refrigerant oil.

(B) O-ring

AC-00010

AC-00344

( C )

( B )

( A )

AC-00268

AC-19

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

GENERAL DESCRIPTION

D: PREPARATION TOOL

CAUTION:
When working on vehicles with the HFC-134a system, only use HFC-134a specified tools and parts.
Do not mix with CFC-12 tools and parts. If HFC-134a and CFC-12 refrigerant or compressor oil is
mixed, poor lubrication will result and the compressor itself may be destroyed.
In order to help prevent mixing HFC-134a and CFC-12 parts and liquid, the tool and screw type and
the type of service valves used are different. The gas leak detectors for the HFC-134a and CFC-12
systems must also not be interchanged.

HFC-134a

CFC-12

Tool & screw type

Millimeter size

Inch size

Valve type

Quick joint type

Screw-in type

Tools and Equipment

Description

Wrench

Various WRENCHES will be required to service any A/C system. A 7
to 40 N·m (0.7 to 4.1 kg-m, 5 to 30 ft-lb) torque wrench with various
crowfoot wrenches will be needed. Open end or flare nut wrenches will
be needed for back-up on the tube and hose fittings.

Applicator bottle

A small APPLICATOR BOTTLE is recommended to apply refrigerant
oil to the various parts. They can be obtained at a hardware or drug
store.

Manifold gauge set

A MANIFOLD GAUGE SET (with hoses) can be obtained from either a
commercial refrigeration supply house or from an auto shop equipment
supplier.

AC-00347

AC-00348

AC-00349

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