SUBARU LEGACY 1999 Service Repair Manual

1. Safety Precautions
A: HFC-134a AIR CONDITIONING
SYSTEM
Component parts of the cooling system,
refrigerant, compressor oil, and other parts are not
the same for the HFC- 134a system and the older
CFC-12 system. Do not interchange parts or liquid.
Vehicles with HFC-134a air conditioning systems,
use only HFC-134a parts that are indicated on a
label attached to the vehicle. Before performing
any maintenance, verify the type of air conditioning
system installed in the vehicle.
B4M0780
B: COMPRESSOR OIL
Do not use any compressor oil that is not specifi-
cally designated for the HFC-134a air conditioning
system; only use ZXL200PG. Also, do not use
HFC-134a compressor oil in the CFC-12 air condi-
tioning system. If compression oils are mixed, poor
lubrication will result and the compressor itself may
be damaged.
Because HFC-134a compressor oil is very hygro-
scopic (easily absorbs moisture), when parts of the
air conditioning system are being removed, quickly
install a blind plug to prevent contact with the out-
side air. Also, always make sure that the service
container for compressor oil is tightly closed except
when in use. Store compressor oil in a tightly
closed steel container.
C: REFRIGERANT
Do not put CFC-12 refrigerant into a HFC-134a air
conditioning system. Also, do not put HFC-134a
refrigerant into a CFC-12 air conditioning system.
If the wrong refrigerant is used, poor lubrication willresult and the compressor itself may be destroyed.
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1. Safety Precautions

D: HANDLING OF REFRIGERANT
Because refrigerant boils at approx. þ30ÉC (þ22ÉF)
at sea level, it is cold enough to give you severe
frostbite. Always wear goggles to protect your eyes
and gloves to protect your hands. Also, even under
the pressures normally found in CFC-12
containers, refrigerant will boil with the addition of
heat. This could raise the pressure inside the con-
tainer to a dangerous level.
Never expose a can of HFC-134a to direct
sunlight, or to temperatures over 40ÉC (104ÉF).
One more thing to remember about HFC-134a is
that when it is exposed to an open flame or to hot
metal, it forms phosgene, a deadly gas. Do not
discharge HFC-134a into the atmosphere on pur-
pose. Always read and follow the precautions on
the HFC-134a bottle.
G4M0979
2. Basic Information
1) The combination of moisture and refrigerant
forms acid, therefore, moisture should not be
allowed to enter the refrigerant.
2) Refrigerant oil readily absorbs moisture,
therefore, keep refrigerant oil containers tightly
capped.
3) The process of evacuating the system is per-
formed to remove small amounts of moisture. This
is accomplished by lowering the pressure inside
the system, which allows the moisture to boil off, in
much the same way that a pot of water will boil
away to nothing given enough time. The evacua-
tion process does not suck the moisture out of the
system.
4) A minimum level of vacuum must be reached to
satisfactorily evacuate the system. This minimum
level of vacuum depends on the temperature
inside the system. The chart below shows the level
of vacuum required to boil water at various tem-
peratures.
Additionally, the vacuum level shown on a gauge
will read approx. 4 kPa (25 mmHg, 1 inHg) less for
each 304.8 m (1,000 ft) above sea level, due to the
decrease in atmospheric pressure at altitude.
Vacuum level required to boil water (at sea level)
Vacuum level required to boil water (at sea level)
Temperature ÉC (ÉF) Vacuum kPa (mmHg, inHg)
1.7 (35) 100.9 (757, 29.8)
7.2 (45) 100.6 (754, 29.7)
12.8 (55) 99.9 (749, 29.5)
18.3 (65) 99.2 (744, 29.3)
23.9 (75) 98.5 (739, 29.1)
29.4 (85) 97.2 (729, 28.7)
35 (95) 95.8 (719, 28.3)
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2. Basic Information

D: HANDLING OF REFRIGERANT
Because refrigerant boils at approx. þ30ÉC (þ22ÉF)
at sea level, it is cold enough to give you severe
frostbite. Always wear goggles to protect your eyes
and gloves to protect your hands. Also, even under
the pressures normally found in CFC-12
containers, refrigerant will boil with the addition of
heat. This could raise the pressure inside the con-
tainer to a dangerous level.
Never expose a can of HFC-134a to direct
sunlight, or to temperatures over 40ÉC (104ÉF).
One more thing to remember about HFC-134a is
that when it is exposed to an open flame or to hot
metal, it forms phosgene, a deadly gas. Do not
discharge HFC-134a into the atmosphere on pur-
pose. Always read and follow the precautions on
the HFC-134a bottle.
G4M0979
2. Basic Information
1) The combination of moisture and refrigerant
forms acid, therefore, moisture should not be
allowed to enter the refrigerant.
2) Refrigerant oil readily absorbs moisture,
therefore, keep refrigerant oil containers tightly
capped.
3) The process of evacuating the system is per-
formed to remove small amounts of moisture. This
is accomplished by lowering the pressure inside
the system, which allows the moisture to boil off, in
much the same way that a pot of water will boil
away to nothing given enough time. The evacua-
tion process does not suck the moisture out of the
system.
4) A minimum level of vacuum must be reached to
satisfactorily evacuate the system. This minimum
level of vacuum depends on the temperature
inside the system. The chart below shows the level
of vacuum required to boil water at various tem-
peratures.
Additionally, the vacuum level shown on a gauge
will read approx. 4 kPa (25 mmHg, 1 inHg) less for
each 304.8 m (1,000 ft) above sea level, due to the
decrease in atmospheric pressure at altitude.
Vacuum level required to boil water (at sea level)
Vacuum level required to boil water (at sea level)
Temperature ÉC (ÉF) Vacuum kPa (mmHg, inHg)
1.7 (35) 100.9 (757, 29.8)
7.2 (45) 100.6 (754, 29.7)
12.8 (55) 99.9 (749, 29.5)
18.3 (65) 99.2 (744, 29.3)
23.9 (75) 98.5 (739, 29.1)
29.4 (85) 97.2 (729, 28.7)
35 (95) 95.8 (719, 28.3)
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2. Basic Information

3. Tools and Equipment
The following section provides information about
the tools and equipment that will be necessary to
properly service the A/C system.
Since equipment may vary slightly depending on
the manufacturer, it is important to always read and
follow the manufacturer's instructions.
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 com-pressor 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
IWRENCH
VariousWRENCHESwill be required to service any A/C sys-
tem. 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.
G4M0571
IAPPLICATOR BOTTLE
A smallAPPLICATOR BOTTLEis recommended to apply
refrigerant oil to the various parts. They can be obtained at a
hardware or drug store.
G4M0572
IMANIFOLD GAUGE SET
AMANIFOLD GAUGE SET(with hoses) can be obtained
from either a commercial refrigeration supply house or from
an auto shop equipment supplier.
G4M0573
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3. Tools and Equipment

Tools and Equipment Description
IREFRIGERANT RECOVERY SYSTEM
AREFRIGERANT RECOVERY SYSTEMis used for the
recovery and reuse of A/C system refrigerant after contami-
nants and moisture have been removed from the refrigerant.
G4M0574
ISYRINGE
A graduated plasticSYRINGEwill be needed to add oil back
into the system. The syringe can be found at a pharmacy or
drug store.
G4M0575
IVACUUM PUMP
AVACUUM PUMP(in good working condition) is necessary,
and may be obtained from either a commercial refrigeration
supply house or an automotive equipment supplier.
G4M0576
ICAN TAP
ACAN TAPfor the 397 g (14 oz) can is available from an
auto supply store.
G4M0577
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3. Tools and Equipment

Tools and Equipment Description
ITHERMOMETER
PocketTHERMOMETERSare available from either industrial
hardware store or commercial refrigeration supply houses.
G4M0578
IELECTRONIC LEAK DETECTOR
AnELECTRONIC LEAK DETECTORcan be obtained from
either a specially tool supply or an A/C equipment supplier.
G4M0579
IWEIGHT SCALE
AWEIGHT SCALEsuch as an electronic charging scale or a
bathroom scale with digital display will be needed if a 13.6 kg
(30 lb) refrigerant container is used.
G4M0580
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3. Tools and Equipment

4. O-ring Connections
A: GENERAL
The following points should be kept in mind when
assembling O-ring connections.
1) Avoid unnecessary handling and contact of
O-rings with your hands, since even clean fingers
contain body acids, which can contaminate the
O-ring surface.
2) Do not handle O-rings with gloves, shop towels,
etc., since lint particles may cling to the O-ring,
possibly causing a leak upon assembly.
3) Always lubricate O-rings before assembly to
allow the O-ring to seat itself properly.
4) Be certain to use torque wrenches when tight-
ening O-ring fittings, because overtightening can
not only damage the O-ring, but it can distort the
tube end as well.
B: REMOVE PROTECTIVE SEALS
1) Just prior to making the connection, remove the
protective seals.
CAUTION:
If for any reason you have to stop before mak-
ing a connection, recap the tube, component or
fitting.
G4M0581
2) Visually inspect the O-ring surface, the O-ring
mating surface, the threads and the connection
points. If a defective part is found, replace it.
The O-ring must sit square against the tube bead.
If necessary, slide the O-ring into proper position
with clean hands.
G4M0582
C: LUBRICATE THE COMPONENTS
For lubrication of the components, use only refrig-
erant oil as described in the appropriate service
manual. Apply oil from an oil squirt gun or other
closed container. Do not use your finger to spread
the oil over the O-ring.
Apply a small amount of refrigerant oil to the top
and sides of the O-ring. The area covered by oil
should include the O-ring and the tube bead.
G4M0583
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4. O-ring Connections

D: TORQUE THE FITTING
Using a back-up wrench in conjunction with a cali-
brated torque wrench, torque the connection to the
midrange of the specification.
After completion of torquing, use a clean shop
towel to remove any excess oil from the connection
or any oil that may have dripped on the vehicle
body or other parts.
CAUTION:
If a leak is suspected after torquing, do not
retighten or retorque the connection. Instead,
disassemble the connection, remove the
O-ring, and inspect the O-ring, threads, joints
and seating surfaces.
G4M0584
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4. O-ring Connections

5. Refrigerant Service Procedure
A: WORK FLOW
B4M1097A
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5. Refrigerant Service Procedure

6. Discharge the System
CAUTION:
The following points should be kept in mind
when discharging the system.
IBe certain that goggles and gloves are worn.
IConnect refrigerant recovery system to
manifold gauge set and remove recycle refrig-
erant from A/C system.
NOTE:
Refer to appropriate refrigerant recovery system
instruction manual for operation.
A: CONNECTING THE MANIFOLD
GAUGE SET
1) Close the high and low side manifold valves.
G4M0585
2) Turn the A/C system ON and turn the IG switch
OFF.
3) Attach the high- and low-pressure manifolds to
the high and low services port on the vehicle.
G4M0586
B: PREPARE FOR DISCHARGING
Connect the center manifold hose to the refrigerant
recovery system to recycle refrigerant.
7. Evacuating and Charging
The following points should be kept in mind when
evacuating and charging with a manifold gauge
set.
1) Be certain that goggles and gloves are worn.
2) If bulk refrigerant [13.6 kg (30 lb) canister] is
used, be certain to weigh the charge amount
carefully, using the correct equipment, to avoid
overcharging the system.
3) The charging procedure described in this sec-
tion begins by charging liquid refrigerant into the
high- pressure side of the system with the engine
off. The procedure is completed by charging refrig-
erant vapor into the low-pressure side of the sys-
tem with the engine running.
CAUTION:
Never open the high-pressure manifold valve
when the engine is running.
A: CONNECT THE GAUGE SET
1) Close the high- and low-pressure manifold
valves.
G4M0596
2) Attach the low-pressure manifold hose to the
low- pressure service port on the vehicle. Check
the low- pressure gauge. If more than 68.6 kPa
(0.70 kg/cm
2, 10 psi) is indicated, discharge the
system prior to charging.
3) Attach the high-pressure manifold hose to the
high- pressure service port on the vehicle.
4) Connect the center hose from the manifold to
the vacuum pump.
5) Turn on the vacuum pump.
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7. Evacuating and Charging