Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Service manual — part 590

AC-19

Refrigerant Recovery Procedure

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

4. Refrigerant Recovery Proce-

dure

A: PROCEDURE

CAUTION:

• During operation, be sure to wear protective

goggles and protective gloves.

• Connect the refrigerant recovery system with

the manifold gauge set to discharge the refrig-

erant from the A/C system and recycle the gas.

• When recycling the discharged refrigerant,

keep service cans on hand. Because the recov-

ery rate with the recovery system is approx.

90%, service cans are necessary to charge the

refrigerant.

• Follow the detailed operation procedure de-

scribed in the operation manual attached to the

refrigerant recovery system.

1) Perform compressor oil return operation. <Ref.

to AC-24, PROCEDURE, Compressor Oil.>

2) Stop the engine.

3) Make sure the valves on low/high pressure sides

of manifold gauge set are fully closed.

4) Install the low/high pressure hoses to the service

ports on the low/high pressure sides of the vehicle

respectively.

5) Connect the center hose to the refrigerant recov-

ery system.

6) Follow the operation manual to activate the re-

frigerant recovery system.

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-pressure side service port
(2) High-pressure side service port
(3) Close

AC-00147

(3)

(2)

(1)

AC-20

Refrigerant Charging Procedure

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

5. Refrigerant Charging Proce-

dure

A: PROCEDURE

CAUTION:

• While working, be sure to wear protective

goggles and protective gloves.

• Air in the cycle can cause insufficient air con-

ditioning, and water in the cycle can cause

clogging in the cycle (icing) and rust. To re-

move this air and water content, use a vacuum

pump to perform evacuation before filling with

refrigerant. By making the inside of the cycle a

vacuum, the water content will evaporate even

at normal temperatures, and can be removed.

1) Close all valves of the manifold gauge.

2) Attach the low pressure side and high pressure

side hoses to the vehicle service port.
CAUTION:

Confirm that the connections are secure.

3) Connect the center manifold hose of the mani-

fold gauge to the vacuum pump.

4) Operate the vacuum pump and open the low

pressure and high pressure side valves. Next, open

the center manifold hose valve, and begin evacua-

tion.
CAUTION:

Make sure to perform evacuation using a vacu-

um 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-pressure side service port
(2) High-pressure side service port
(3) Close

(1) Vacuum pump
(2) Open

AC-00147

(3)

(2)

(1)

AC-00148

(1)

(2)

AC-21

Refrigerant Charging Procedure

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

5) Perform evacuation for 5 minutes or more, and

when the low pressure gauge needle reaches –100.0

kPa (–750 mmHg, –29.5 inHg) or higher, close the

center manifold hose valve, and stop the vacuum

pump.

6) Leave alone for 5 to 10 minutes after closing the

low pressure side and high pressure side valves,

and check whether there is any change in the low

pressure gauge needle indication. If the needle po-

sition changes, this indicates a leak. Check the

pipe and hose connections, and repair the location

with the problem. In this case, repeat again from

step 1).

7) If there is no leakage, continue evacuation for

additional 20 to 30 minutes.

8) Close all valves and stop the vacuum pump.

9) Follow the can tap operation manual, install to

the refrigerant can.

10) Disconnect the center manifold hose from the

vacuum pump, and connect the hose to the tap

valve.

11) When a 13.6 kg (30 lb) refrigerant container is

used, measure the amount of refrigerant with a re-

frigerant charging scale, and connect with the cen-

ter manifold hose.

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

13) Loosen the center manifold hose connection on

the manifold gauge for a few seconds (if there is a

purge valve on the manifold gauge, push this in-

stead) to allow the air in the center manifold hose to

be bled by the refrigerant pressure.

14) Open the high pressure side and low pressure

side valves of the manifold gauge to fill with refrig-

erant.
CAUTION:

When filling with the engine running, do not

open the high pressure side valve. Always fill

from the low pressure side.

15) When the gauge needle reaches approximate-

ly 200 kPa (1,500 mmHg, 59.1 inHg), close all

valves.

16) Using a leak tester, check for refrigerant leaks

in the system.

17) After checking that there are no refrigerant

leaks, fill with refrigerant up to the specified

amount.

18) If the HFC-134a supply container becomes

empty, close all valves, and close the can tap valve

to replace the empty container. After replacing with

a new HFC-134a supply container, perform air

purge, and resume the filling operation.

19) If the refrigerant filling efficiency drops, close all

valves.

20) Check that both the low pressure and high

pressure valves are closed. Start the engine with

the A/C switch OFF.

(1) Tap valve
(2) To the center manifold hose

(1) Refrigerant container (HFC-134a)
(2) Weight scale

AC-00214

(1)

(2)

AC-00215

(1)

(2)

(1) Open (low pressure)
(2) Open (high pressure)

AC-00216

(1)

(2)

AC-00217

AC-22

Refrigerant Charging Procedure

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

21) To prevent damage to the compressor, push

the A/C switch ON-OFF quickly a few times.

22) Set up the vehicle to the following status:
CAUTION:

When filling with the engine running, do not

open the high pressure side valve.

Always fill from the low pressure side valve.

• A/C switch: ON

• Engine running at 1,500 rpm

• Fan speed control dial: HI

• Temperature control dial: MAX COOL

• FRESH/RECIRC switch: RECIRC

• Window: open

23) Open the low pressure side valve and fill with

refrigerant up to the specified amount.

24) After filling with refrigerant, close all valves and

disconnect the hose from the service port.

25) Attach the cap to the service port.