Subaru Legacy III (2000-2003 year). Manual - part 859

AC-24

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

REFRIGERANT CHARGING PROCEDURE

4. Refrigerant Charging Proce-

dure

A: OPERATION

CAUTION:
• During operation, be sure to wear safety gog-
gles and protective gloves.
• If air is mixed in refrigeration cycle, poor
cooling may result, and also if moisture is
mixed in refrigeration cycle, clogging (freezing)
or rust may result.
Before charging the refrigerant, evacuate the
system using vacuum pump to remove air and
moisture in the system. Moisture can be evapo-
rated and removed easily even at normal tem-
perature, if the system is evacuated using
vacuum pump.
1) Close all valves of manifold gauge.

2) Install the low-/high-pressure hoses to corre-
sponding service ports on vehicle.

CAUTION:
Be sure that the hoses are securely connected.
3) Connect the center hose of manifold gauge with
vacuum pump.
4) Activate the vacuum pump and then open the
valves on low-/high-pressure sides.

CAUTION:
Be sure to evacuate the system using vacuum 
pump.

L: Low-pressure gauge

H: High-pressure gauge

(1) Low-pressure valve

(2) Vacuum pump valve

(3) High-pressure valve

(4) For low-pressure

(5) For vacuum pump

(6) For high-pressure

AC-00146

(2)

(4)

(5)

(6)

(3)

(3)

(2)

(1)

H

L

(1)

(1) Low service port

(2) High service port

(3) Close

(1) Vacuum pump

(2) Open

AC-00147

(3)

(2)

(1)

AC-00148

(1)

(2)

AC-25

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

REFRIGERANT CHARGING PROCEDURE

5) After at least 5 minutes of evacuation, if the low-
pressure gauge reading shows 100.0 kPa (750
mmHg, 29.5 inHg) or higher, close the valves on
center hose to stop the vacuum pump.
6) Leave it at least 5 to 10 minutes after closing the
valves on low-/high-pressure sides, and then check
the low-pressure gauge reading for any changes.
When the gauge reading changes, this is a sign of
leakage. Check the pipe or hose connector points,
and repair if necessary. Repeat the procedure from
1) after repairing the faulty part.
7) If there are no leaks, further evacuate the sys-
tem 20 to 30 minutes.
8) Close all valves and stop the vacuum pump.
9) Following the can tap operation manual instruc-
tions, install it to refrigerant can.

10) Disconnect the vacuum pump from center
hose, and connect the hose to tap valve.
11) When a refrigerant recovery container is used,
measure the refrigerant amount in use using a
weighting scale before connecting to center hose.

12) Open the valve on HFC-134a source.

13) Loosen the center hose connection on manifold
gauge (if applicable, press a purge valve on mani-
fold gauge) only for a couple of seconds to allow
the air in the center hose to escape by the refriger-
ant.

14) Make sure that the high-pressure valve of man-
ifold gauge is closed, and then open the low-pres-
sure side valve only to charge the refrigerant.

CAUTION:
Do not open the high-pressure valve. Be sure to 
open the low-pressure valve.
15) Close the low-pressure valve when the low-
pressure gauge reading reaches 200 kPa (1,500
mmHg, 59.1 inHg).
16) Using a leak tester, check the system for refrig-
erant leaks.
17) After confirming that there are no leaks with the
leak test, charge the required amount of refrigerant.
18) If the HFC-134a source is empty, close the low-
pressure valve and then close the valve on can tap
before replacing the empty source. Restart charg-
ing operation after replacing the HFC-134a source
with a new one and purging.
19) Close the low-pressure valve if the charge rate
of refrigerant becomes worse.
20) Confirm that both the low-/high-pressure
valves are closed. Start the engine with A/C switch
OFF.
21) Quickly repeat A/C switch ON-OFF cycles a
few times to prevent initial compressor damage.

(1) Tap valve

(2) Connect to center hose

(1) Refrigerant recovery container

(2) Weighting scale

AC-00214

H F C

1 3 4 a

( 1 )

( 2 )

AC-00215

( 1 )

( 2 )

(1) Open

(2) Close

AC-00216

AC-00217

(1)

(2)

AC-26

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

REFRIGERANT CHARGING PROCEDURE

22) Set up the vehicle to the following status:
• A/C switch ON
• Engine running at 1,500 rpm
• Blower speed setting to “Hi”
• Temperature setting to “MAX COOL”
• Air inlet setting to “RECIRC”
• Window open 
23) Open the low-pressure valve and charge the
specified amount of refrigerant.
24) Close all valves and disconnect the hoses from
service port after charging the refrigerant.
25) Install the cap to service port.

AC-27

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

REFRIGERANT LEAK CHECK

5. Refrigerant Leak Check

A: INSPECTION

1) Operate the A/C system for approx. 10 minutes,
and confirm that the high-side pressure shows at
least 690 kPa (7.03 kg/cm

2

, 100 psi). Then stop the

engine to start the leak test.
2) Starting from the connection between the high-
pressure tube and evaporator, check the system
for leaks along the high-pressure side through the
compressor. The following items must be checked
thoroughly.
• Connection between the tube and tube fitting

• Connection between 2 parts

• Connection between the tube and nut

3) Check the joint and seam between the pressure
switch (dual switch) and receiver dryer.
4) Check the connections between the condenser
and tubes, and welded joints on the condenser.
The leak tester may detect the oil on the condenser
fins as a leak.

5) Check the joint between the compressor and
hoses.
6) Check the machined area of compressor and
other joints on the compressor.
7) Check the thermal limiter (if equipped) on the
compressor housing.
8) Check the compressor shaft seal at the area
near the center of compressor clutch pulley.
Some shaft seals show a slight amount of leakage
about 28 g (1.0 oz) per year. This is not a problem.
9) Starting from the connection between the low-
pressure tube and evaporator, check the system
for leakage along the high-pressure side through
the compressor. The following items must be
checked thoroughly.
• Connection between the tube and tube fitting
• Connection between 2 parts
• Connection between the tube and nut

10) Visually check the rubber area of the flexible
hose for cracks.
Check the entire length of the flexible hose, espe-
cially the connection with the metal hose end.

CAUTION:
Carefully check the external surface of hoses 
and tubes at approx. 25 mm (0.98 in) per sec-
ond. 

11) Disconnect the drain hose from the evaporator
case, and check the hose end for at least 10 sec-
onds.
After the test is finished, reconnect the drain hose.

AC-00269

AC-00270

AC-00271

(A) Flexible hose

AC-00035

AC-00036

( A )