1999 SUBARU LEGACY Service Repair Manual

Item Specifications
Thermo control amplifier
working temperature
(Evaporator outlet air)
B4M0756B
3
[S1A0]4-7SPECIFICATIONS AND SERVICE DATA
1. Air Conditioning System

1. Air Conditioning System
B4M0757B
(1) Receiver drier bracket
(2) Pipe (Receiver drier Ð Evapora-
tor unit)
(3) Receiver drier
(4) Evaporator unit
(5) Hose (Low-pressure)
(6) A/C relay(7) Fuse
(8) Hose (High-pressure)
(9) Compressor
(10) Condenser
(11) Pipe (Condenser-Receiver drier)Tightening torque: N´m (kg-m, ft-lb)
T1:
7.4±2.0 (0.75±0.2, 5.4±1.4)
T2:15±5 (1.5±0.5, 10.8±3.6)
T3:15±3 (1.5±0.3, 10.8±2.2)
T4:25±5 (2.5±0.5, 18.1±3.6)
4
4-7[C100]COMPONENT PARTS
1. Air Conditioning System

2. Evaporator Unit
B4M0086B
(1) Thermo control amplifier
(2) Case upper
(3) Cooling module
(4) Pipe
(5) Seat
(6) Expansion valve(7) Drain hose
(8) Case lower
(9) Resistor
(10) Resistor bracketTightening torque: N´m (kg-m, ft-lb)
T1:
7.4±2.0 (0.75±0.2, 5.4±1.4)
T2:10±3 (1.0±0.3, 7.2±2.2)
T3:15±5 (1.5±0.5, 10.8±3.6)
T4:20±5 (2.0±0.5, 14.5±3.6)
5
[C200]4-7COMPONENT PARTS
2. Evaporator Unit

3. Compressor
B4M0758B
(1) Alternator bracket
(2) Alternator
(3) Alternator bracket nut
(4) Bracket
(5) Compressor bracket lower(6) Compressor
(7) Idler pulley ASSY
(8) Compressor bracket upperTightening torque: N´m (kg-m, ft-lb)
T1:
23.0±4.4 (2.35±0.45, 17.0±3.3)
T2:29±4 (3.0±0.4, 21.7±2.9)
T3:35±4 (3.6±0.4, 26.0±2.9)
6
4-7[C300]COMPONENT PARTS
3. Compressor

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.
7
[W1C0]4-7SERVICE PROCEDURE
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)
8
4-7[W1D0]SERVICE PROCEDURE
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)
8
4-7[W1D0]SERVICE PROCEDURE
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
9
[W300]4-7SERVICE PROCEDURE
3. Tools and Equipment