1999 SUBARU LEGACY Service Repair Manual

C: PURGE THE CENTER HOSE
CAUTION:
Be certain that goggles and gloves are worn.
1) Verify that all three hose connections are tight
at the manifold gauge set.
G4M0603
2) Open the valve on the HFC-134a source.
3) Loosen the center hose connection at the mani-
fold and allow the HFC-134a to escape for no more
than two or three seconds, then quickly retighten
the hose fitting at the manifold.
D: INITIAL CHARGING THROUGH
THE HIGH SIDE
1) Connect a tachometer to the engine.
2) With the engine off, start charging by slowly
opening the high-pressure manifold valve.
NOTE:
The initial charge rate can be increased by
immersing the can in lukewarm [Below 38ÉC
(100ÉF)] water for a short time.
G4M0604
E: CHECK THE GAUGE READINGS
When both the high- and low-pressure gauge read-
ings are about equal, or the HFC-134a source is
empty, or the system has been filled to
specifications, close the high- pressure manifold
valve.
G4M0605
F: ADD ADDITIONAL CANS
If the HFC-134a source is exhausted, first close
the high- pressure manifold valve, second, close
the can tap valve, then slowly purge the refrigerant
from the service hose by loosening the fitting at the
can tap.
G: COMPLETE CHARGING
THROUGH THE LOW SIDE
1) Verify that the high-pressure manifold valve is
closed (should have already been closed).
2) Verify that the low-pressure manifold valve is
closed (should have already been closed).
G4M0606
3) With the A/C switch off and the windows rolled
down, start the engine and run at idle rpm.
4) Set the A/C controls on maximum cool and set
the blower speed on the highest setting.
17
[W7G0]4-7SERVICE PROCEDURE
7. Evacuating and Charging

5) Quickly turn the A/C switch on-off-on-off a few
times to prevent initial compressor damage due to
ªload shock.º Finish this operation with the A/C
switch in the ON position.
G4M0607
6) Raise engine rpm to approximately 1,500 rpm.
H: CHARGE THE SYSTEM
1) With the refrigerant source connected and the
service hose purged, slowly open the low-pressure
manifold valve, while checking the low-pressure
gauge reading.
CAUTION:
The refrigerant source must be positioned for
vapor (valve up).
G4M0608
2) Keep the low side pressure below 276 kPa
(2.81 kg/cm2, 40 psi) by using the low-pressure
manifold valve to regulate the flow of refrigerant
into the system.
3) When the system is fully charged, close the
low- pressure manifold valve.
4) Close the valve at the refrigerant source.
IRefrigerant capacity
Unit: kg (lb)
Refrigerant Minimum Maximum
HFC-134a 0.55 (1.21) 0.65 (1.43)
I: COMPLETE ALL SYSTEM
CHECKS
1) Evaluate the system performance. [W1000].>2) Perform leak detection test. [W800].>
CAUTION:
IAlways perform leak checking in an environ-
ment free of refrigerant pollution.
IDo not disconnect the high- or low-pressure
hoses from the vehicle before leak checking.
J: DISCONNECT THE MANIFOLD
GAUGE SET
Remove the high- or low-pressure hoses from the
service ports and install the service port caps.
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4-7[W7H0]SERVICE PROCEDURE
7. Evacuating and Charging

8. Leak Testing
A: INSPECTION
The following points should be kept in mind when
conducting a refrigerant leak test.
1) The A/C system to be tested must have an
adequate refrigerant charge to begin with.
2) The area where the leak test is conducted must
be free of wind and drafts, with still air being the
ideal condition.
3) The atmosphere where the leak test is con-
ducted must be free of refrigerant contamination.
4) Operate the A/C system for approx. 10 minutes,
then turn the engine off an begin the leak test.
5) Refrigerant gas is heavier than air, therefore
always hold the probe below the connection being
tested.
6) When checking for a leak along a length of
hose or tube, the leak detector probe must be
moved slowly, approx. 25 mm (1 in) per second
making sure probe does not come in contact with
the component being tested.
7) When checking for a leak at a certain point, the
leak detector probe must be held at that point for
at least 5 seconds.
1. CHECK THE SYSTEM PRESSURE
With gauges connected to the A/C system, operate
the A/C and confirm that the high side pressure is
above 690 kPa (7.03 kg/cm
2, 100 psi). If not,
evacuate and charge the system before leak
checking (refer to evacuation and charging sec-
tions).
G4M0609
2. CLEAN CONNECTIONS BEFORE
TESTING
Before testing, use a clean shop towel to wipe off
refrigerant oil, dirt, or foreign material from all of the
connections and components to be tested.
NOTE:
Since refrigerant oil absorbs refrigerant, excess oil
on or near a connection may falsely signal a leak.
3. CALIBRATE LEAK DETECTOR
Refer to the manufacturer's instructions for the par-
ticular type of detector used and calibrate the
instrument.
CAUTION:
Always make sure that the probe tip filter is
clean and free of contamination.
B4M0089
4. LEAK TEST (HIGH-PRESSURE SIDE)
Operate the A/C system for approx. 10 minutes,
then turn the engine off and begin the leak test.
1) Begin at the connection of the high-pressure
tube to the evaporator, and work your way along
the high- pressure side of the system to the com-
pressor. There are three places to check on each
tube connection.
2) Check the area.
ICheck the area where the fitting joins the tube.
G4M0612
ICheck the area where the two parts of the fitting
join each other.
G4M0613
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[W8A4]4-7SERVICE PROCEDURE
8. Leak Testing

ICheck the area where the nut joins the tube.
G4M0614
3) Check the area of the sight glass and pressure
switch (dual switch), and also check the seams of
the receiver drier.
4) Check the connections of the tubes to the
condenser, and also check any welded joints on
the condenser.
CAUTION:
An oily area on the fins of the condenser may
indicate a leak.
5) Check the area where the hoses attach to the
compressor.
6) Check around the machined portions of the
compressor (where the compressor sections join
each other).
7) If equipped, check the thermal limiter on the
compressor housing.
8) Check the compressor shaft seal by probing
near the center of the compressor clutch pulley.
NOTE:
Some shaft seals have a very slight amount of
normal leakage [approximately 28 g (1.0 oz) per
year].
5. LEAK TEST (LOW-PRESSURE SIDE)
1) Begin at the connection of the low-pressure
tube to the evaporator, and work your way along
the low-pressure of the system to the compressor.
There are three places to check on each tube con-
nection.
2) Check the area.(1) Check the area where the fitting joins the
tube.
G4M0615
(2) Check the area where the two parts of the
fitting join each other.
(3) Check the area where the nut joins the tube.
G4M0616
6. CHECK THE FLEXIBLE HOSES
Visually inspect the rubber portions of the flexible
hoses for cracking. Probe the rubber section,
including the ends of any insulators or protectors
which may cover sections of the rubber hose, and
near the ends where the rubber meets the metal
collar.
NOTE:
Be certain to move the probe slowly [approximately
25 mm (1 in) per second] when probing along any
length of hose or tube.
G4M0617
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4-7[W8A5]SERVICE PROCEDURE
8. Leak Testing

7. CHECK THE EVAPORATOR
ASSEMBLY
1) Use one or both of the following methods to
check the evaporator assembly.
2) Remove the drain hose from the case drain
nipple. Hold the probe at the end of the case drain
nipple for at least 10 seconds. Be certain to recon-
nect the drain hose when finished.
3) With the ignition key in the ªACCº position, run
the blower on high speed for 1 minute, then turn
the blower off. Place the probe in the center instru-
ment panel vent, an turn the blower on low speed
for 1 to 2 seconds, then turn the blower off. Leave
the probe in the vent for at least 10 seconds.
G4M0618
8. CHECK THE SERVICE PORT CAPS
Visually inspect the inside of the service port caps.
Make sure the rubber seal is in place on the inside
of the caps. Disconnect the gauges from the
vehicle and install the service port caps.
G4M0619
9. Lubrication
A: ADJUSTMENT
1. SYSTEM OIL STABILIZATION
1) Prior to opening the refrigerant system for
repairs (except compressor seizure) the system
must be stabilized for correct oil replenishment.
2) Follow these procedures:
(1) Engine speed set to 1,500 rpm
(2) A/C ªONº
(3) Air source to recirculate
(4) Blower in 4th or high speed position
IMake sure the air entering the evaporator is
above 26.7ÉC (80ÉF).
IThe discharge (high) side pressure must be
above 588 kPa (6 kg/cm
2, 85 psi).
(5) Operate the A/C for 10 minutes.
2. SYSTEM DISCHARGE
Slowly, discharge the system starting with the high-
pressure side until the pressure drops below 345
kPa (3.52 kg/cm
2, 50 psi), then open the low-pres-
sure side.
B: REPLACEMENT
1. OIL REPLACEMENT
1) After stabilization and discharge, replace the
component, adding the appropriate amount of oil
(ZXL200PG) to the new component before instal-
lation.
Evaporator11 4 m(3.9 US fl oz, 4.0
Imp fl oz)
Receiver drier5m(0.2 US fl oz, 0.2 Imp
fl oz)
Condenser2m(0.07 US fl oz, 0.07
Imp fl oz)
Hose1m(0.03 US fl oz, 0.04
Imp fl oz)
2) If the compressor is replaced (after stabiliza-
tion):
(1) Drain and measure the oil from the original
compressor.
(2) Drain the oil from the replacement compres-
sor and refill with the same amount that was
drained from the original [20 m(0.7 US fl oz,
0.7 Imp fl oz) minimum]. Always use ZXL200PG
for the replacement oil.
21
[W9B1]4-7SERVICE PROCEDURE
9. Lubrication

7. CHECK THE EVAPORATOR
ASSEMBLY
1) Use one or both of the following methods to
check the evaporator assembly.
2) Remove the drain hose from the case drain
nipple. Hold the probe at the end of the case drain
nipple for at least 10 seconds. Be certain to recon-
nect the drain hose when finished.
3) With the ignition key in the ªACCº position, run
the blower on high speed for 1 minute, then turn
the blower off. Place the probe in the center instru-
ment panel vent, an turn the blower on low speed
for 1 to 2 seconds, then turn the blower off. Leave
the probe in the vent for at least 10 seconds.
G4M0618
8. CHECK THE SERVICE PORT CAPS
Visually inspect the inside of the service port caps.
Make sure the rubber seal is in place on the inside
of the caps. Disconnect the gauges from the
vehicle and install the service port caps.
G4M0619
9. Lubrication
A: ADJUSTMENT
1. SYSTEM OIL STABILIZATION
1) Prior to opening the refrigerant system for
repairs (except compressor seizure) the system
must be stabilized for correct oil replenishment.
2) Follow these procedures:
(1) Engine speed set to 1,500 rpm
(2) A/C ªONº
(3) Air source to recirculate
(4) Blower in 4th or high speed position
IMake sure the air entering the evaporator is
above 26.7ÉC (80ÉF).
IThe discharge (high) side pressure must be
above 588 kPa (6 kg/cm
2, 85 psi).
(5) Operate the A/C for 10 minutes.
2. SYSTEM DISCHARGE
Slowly, discharge the system starting with the high-
pressure side until the pressure drops below 345
kPa (3.52 kg/cm
2, 50 psi), then open the low-pres-
sure side.
B: REPLACEMENT
1. OIL REPLACEMENT
1) After stabilization and discharge, replace the
component, adding the appropriate amount of oil
(ZXL200PG) to the new component before instal-
lation.
Evaporator11 4 m(3.9 US fl oz, 4.0
Imp fl oz)
Receiver drier5m(0.2 US fl oz, 0.2 Imp
fl oz)
Condenser2m(0.07 US fl oz, 0.07
Imp fl oz)
Hose1m(0.03 US fl oz, 0.04
Imp fl oz)
2) If the compressor is replaced (after stabiliza-
tion):
(1) Drain and measure the oil from the original
compressor.
(2) Drain the oil from the replacement compres-
sor and refill with the same amount that was
drained from the original [20 m(0.7 US fl oz,
0.7 Imp fl oz) minimum]. Always use ZXL200PG
for the replacement oil.
21
[W9B1]4-7SERVICE PROCEDURE
9. Lubrication

10. Performance Test
A: INSPECTION
1. VEHICLE SET UP
In order to obtain meaningful test results, the
vehicle must be set up to meet the following con-
ditions.
IVehicle in shade
INo wind
IAll vehicle doors closed
IFront windows opened
IHood opened
IEngine speed set at 1,500 rpm.
IA/C ON
ITemperature control lever Ð Maximum cold
IAir source Ð Recirculation
IBlower speed Ð 4th position (High)
IOperate A/C for 10 minutes (Minimum) before
taking measurement.
2. MEASUREMENTS
After 10 minutes (Minimum) of A/C operation and
using accurate test equipment, take the following
measurements (in order).
1) Evaporator intake air temperature at recircula-
tion door.
2) Evaporator discharge air temperature at center
grill.
3) Condenser (Ambient) intake air temperature
measured 0.9 m (3 ft) in front and in line with the
center of the condenser.
4) Suction (Low) side pressure
5) Discharge (High) side pressure
NOTE:
If only one thermometer is available; 1)take the
ambient measurement first; then 2)the intake air;
and 3)discharge air temperature.
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4-7[W10A1]SERVICE PROCEDURE
10. Performance Test

3. MEASUREMENT STANDARD BY VERSES
Compare temperature and pressure measurements with the established standards shown in the following
charts.
B4M0371A
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[W10A3]4-7SERVICE PROCEDURE
10. Performance Test