Refrigerant Charging Procedure: Operation

WARNING: This page is about a different car, the 2003 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

During operation, be sure to wear safety goggles and protective gloves.
Before charging the refrigerant, evacuate the system to remove small amounts of moisture remaining in the system.
The moisture in the system can be completely evacuated only under the minimum vacuum level. The minimum vacuum level affects the temperature in the system.
The list below shows the vacuum values necessary to boil water in various temperature. In addition, the vacuum levels indicated on the gauge are approximately 3.3 kPa (25 mmHg, 0.98 inHg) lower then those measured at 304.8 m (1,000 ft) above sea level.

Fig 1: Vacuum Level Required To Boil Water Chart (At Sea Level)
Courtesy of SUBARU OF AMERICA, INC.

Close the valves on low-high-pressure sides of the manifold gauge.

Fig 2: Closing Valves On Low/High-Pressure Sides Of Manifold Gauge Set
Courtesy of SUBARU OF AMERICA, INC.
Install the low-high-pressure hoses to the corresponding service ports on the vehicle respectively.
Connect the center hose of the manifold gauge set with the vacuum pump.
Carefully open the valves on the low-high-pressure sides to activate the vacuum pump.

Fig 3: Steadily Open Valves On Low/High-Pressure Sides To Activate Vacuum Pump
Courtesy of SUBARU OF AMERICA, INC.
After the low-pressure gauge reaches 100.0 kPa (750 mmHg, 29.5 inHg) or higher, evacuate the system for approximately 15 minutes.

Fig 4: Evacuating System For Approximately 15 Minutes
Courtesy of SUBARU OF AMERICA, INC.
After 15 minutes of evacuation, if the reading shows 100.0 kPa (750 mmHg, 29.5 inHg) or higher, close the valves on the both sides to stop the vacuum pump.

Fig 5: Closing Valves On Both Sides To Stop Vacuum Pump
Courtesy of SUBARU OF AMERICA, INC.
Note the low-pressure gauge reading.

Fig 6: Inspecting & Noting Low-Pressure Gauge Reading After Evacuating
Courtesy of SUBARU OF AMERICA, INC.
Leave it at least 5 minutes, and then check the low-pressure gauge reading for any changes.
When a gauge indicator shows near to zero point, this is a sign of leakage. Check pipe connector points, repair them, make sure there is no leakage by air bleeding.
Following the can tap operation manual instructions, install it to the refrigerant can.

Fig 7: Installing Can Tap Onto Refrigerant Can
Courtesy of SUBARU OF AMERICA, INC.
Disconnect the center manifold hose from the vacuum pump, and connect the hose to the tap valve.
When a 13.6 kg (30 lb) refrigerant container is used, measure the refrigerant amount in use using a weight scale.

Fig 8: Measuring Refrigerant Amount In Use Using A Weighting Scale When Refrigerant Container Is Used
Courtesy of SUBARU OF AMERICA, INC.
Confirm that all the 3 hoses are tightly connected to the manifold gauge set.

Fig 9: Checking All 3 Hoses Are Tightly Connected To Manifold Gauge Set
Courtesy of SUBARU OF AMERICA, INC.
Open the valve on the HFC-134a source.
Loosen the center hose connection on the manifold gauge set (if applicable, press a purge valve on the manifold gauge set) only for a couple of seconds to allow the air in the center hose to escape by the refrigerant.
Carefully open the high-pressure valve with the engine stopping.
CAUTION: Do not open the low-pressure valve.

Fig 10: Carefully Opening High-Pressure Valve With Engine Running
Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Never run the engine during charging from the high-pressure side.
Close the high-pressure valve when the low-pressure gauge reaches 98 kPa (1 kg/cm² , 14 psi). Using a leak tester, check the system for leaks.
If any leakage is found after the refrigerant recovery is completed, repair the applicable area.
After confirming that there are no leaks with the leak test, charge the required amount of refrigerant.
CAUTION: Never run the engine during charging from the high-pressure side.
Close the high-pressure valve when;
- the readings of low-high-pressure gauges become almost equal, after the charging speed is reduced,
- the HFC-134a source becomes empty, or
- the system is filled with the gas.
Fig 11: Checking Readings Of Low & High-Pressure Gauges Become Almost Equal
Courtesy of SUBARU OF AMERICA, INC.
If the HFC-134a source is empty, close the high-pressure valve, close the valve on the can tap, and replace the HFC-134a source with a new one to restart the operation.

Fig 12: Replacing HFC-134a Source If Empty
Courtesy of SUBARU OF AMERICA, INC.
Confirm that both the low-high-pressure valves can be closed. Start the engine with the A/C switch OFF.
Quickly repeat ON-OFF cycles a few times to prevent initial compressor damage.
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 "RECIRCULATION"
- Windows open
While reading the low-pressure gauge, carefully open the low-pressure valve with the refrigerant source connected and the service hose purged.
CAUTION: Never open the high-pressure valve with the engine is running.

Fig 13: Carefully Opening Low-Pressure Valve With Refrigerant Source Connected
Courtesy of SUBARU OF AMERICA, INC.
Adjust the refrigerant flow to maintain the pressure on the low-pressure side at 276 kPa (2.81 kg/cm² , 40 psi) max.
After the system is fully charged, close the low-pressure valve.
Close the valve on the refrigerant source.

Fig 14: Refrigerant Amount Chart
Courtesy of SUBARU OF AMERICA, INC.
Disconnect the hose from the service port, and install the service port cap.