Charging New R-134a Refrigerant

WARNING: This page is about a different car, the 2004 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

Install the manifold gauge set.
Connect the tap pin side of the charging hose to the air purge valve of the manifold gauge.
Connect the vacuum pump hose to the center joint of the manifold gauge.
Connect the vacuum pump hose to the vacuum pump.
Connect the charging hose to the refrigerant tank.
Place the refrigerant tank on the scale.

Fig 1: Connecting Tap Pin Side Of Charging Hose To Air Purge Valve Of Manifold Gauge
Courtesy of MAZDA MOTORS CORP.
Open all the valves of the manifold gauge.
CAUTION:
- Close the manifold gauge valve immediately after stopping the vacuum pump. If the valve is left open, the vacuum pump oil will back flow into the refrigeration cycle and cause a decrease in the efficiency of the air conditioner.
Fig 2: Opening Manifold Gauge Valves (With Refrigerant Tank Valve Closed)
Courtesy of MAZDA MOTORS CORP.
Start the vacuum pump and let it operate for15 min.
Verify that high-and low-pressure side readings of the manifold gauge are at -101 kPa {-760 mmHg, -29.9 inHg}. Close each valve of the manifold gauge.

Fig 3: Closing Each Manifold Gauge Valve
Courtesy of MAZDA MOTORS CORP.
Stop the vacuum pump and wait for 5 min.
Inspect the high-and low-pressure side readings of the manifold gauge.
- If the reading has changed, inspect for leakage and then repeat from Step 7.
- If the reading has not changed, go to next step.
Open the valve of the refrigerant tank.
Weigh the refrigerant tank to charge the suitable amount of refrigerant.
Regular amount of refrigerant (approx. quantity) 430 g {15.2 oz}
WARNING:
- If the refrigerant system is charged with a large amount of refrigerant when checking for gas leakage, and if any leakage should occur, the refrigerant will be released into the atmosphere. In order to prevent the accidental release of refrigerant which can destroy the ozone layer in the stratosphere, follow the proper procedures and charge with only a small amount of refrigerant when checking for gas leakage.
- If charging the system with refrigerant by service cans or refrigerant tank, running the engine with the high-pressure side valve open is dangerous. Pressure within the service cans or refrigerant tank will increase and they could explode, scattering metal fragments and liquid refrigerant that can seriously injure you. Therefore, do not open the high-pressure side valve while the engine is running.
Open the low-pressure side valve of the manifold gauge.

Fig 4: Opening Low-Pressure Side Valve Of Manifold Gauge & Refrigerant Tank Valve
Courtesy of MAZDA MOTORS CORP.
When the high-pressure side reading increases to 98 kPa {1.0 kgf/cm ² , 14 psi}, close the low-pressure side valve of the manifold gauge.

Fig 5: Closing Low-Pressure Side Valve Of Manifold Gauge When High-Pressure Side Reading Increases To 98 kPa
Courtesy of MAZDA MOTORS CORP.
Inspect for leakage from the cooler pipe/hose connections using a gas leak tester.
- If there is no leakage, go to Step 18.
- If leakage is found at a loose joint, tighten the joint, go to next step.
Inspect for leakage again.
- If there is no leakage after tightening the joint, go to next step.
- If there is still a leakage at the same joint, discharge the refrigerant and then repair the joint. Repeat the charging procedure from Step 7.
WARNING:
- If charging the system with refrigerant by service cans or refrigerant tank, running the engine with the high-pressure side valve open is dangerous. Pressure within the service cans or refrigerant tank will increase and they could explode, scattering metal fragments and liquid refrigerant that can seriously injure you. Therefore, do not open the high-pressure side valve while the engine is running.
Open the low-pressure side valve of the manifold gauge and charge with refrigerant until the weight of refrigerant tank has decreased 200 g {7.06 oz} from the amount in Step 13.

Fig 6: Opening & Charging Low-Pressure Side Valve Of Manifold Gauge (Until 200 G Weight Drop Of Refrigerant Tank)
Courtesy of MAZDA MOTORS CORP.
Close the low-pressure side valve of the manifold gauge.
WARNING:
- If charging the system with refrigerant by service cans or refrigerant tank, running the engine with the high-pressure side valve open is dangerous. Pressure within the service cans or refrigerant tank will increase and they could explode, scattering metal fragments and liquid refrigerant that can seriously injure you. Therefore, do not open the high-pressure side valve while the engine is running.
Fig 7: Closing Low-Pressure Side Valve Of Manifold Gauge
Courtesy of MAZDA MOTORS CORP.
Start the engine and actuate the A/C compressor.
Open the low-pressure side valve of the manifold gauge and charge with refrigerant until the weight of the refrigerant tank has decreased 430 g {15.2 oz} from the amount in Step 13.

Fig 8: Opening & Charging Low-Pressure Side Valve Of Manifold Gauge (Until 430 G Further Weight Drop Of Refrigerant Tank)
Courtesy of MAZDA MOTORS CORP.
Close the low-pressure side valve of the manifold gauge and the valve of the refrigerant tank.
Stop the engine and A/C compressor.
Inspect for leakage using a gas leak tester.
- If there is no leakage, go to Step 26.
- If leakage is found at a loose joint, tighten the joint, then go to next step.
Inspect for leakage again.
- If there is still leakage after tightening the joint, go to next step.
- If there is still leakage at the same joint, discharge the refrigerant and then repair the joint. Repeat the charging procedure from Step 7.
Remove the manifold gauge set.
Install the caps to the charging valves.

Fig 9: Installing Caps To Charging Valves
Courtesy of MAZDA MOTORS CORP.