Honda Civic Service Manual: A/C System Evacuation

Air conditioning refrigerant or lubricant vapor can irritate your eyes, nose, or throat.

Be careful when connecting service equipment.

Do not breathe refrigerant or vapor.

If accidental system discharge occurs, ventilate the work area before resuming service.

Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

Do not allow moisture to contaminate the A/C system oil. Moisture in the oil is difficult to remove, and it can damage the A/C compressor.

Using a compact electronic vacuum gauge may decrease the required evacuation time because you can measure actual moisture level with this tool.

If the vacuum level remains stable for at least three minutes, all moisture in the system has been removed.

A slow increase in the micron reading means there is still moisture boiling out of the system. Restart the vacuum pump and continue evacuating.

A quick increase of micron levels indicates a leak is present in the system or your service equipment. Determine the cause and correct the leak before continuing.

1.

Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown, following the equipment manufacturer's instructions.

1.

Recover the refrigerant from the A/C system.

2.

Measure the amount of refrigerant oil removed from the A/C system after the recovery process is completed. Be sure to put the same amount of new refrigerant oil back into the A/C system before charging.

1.

Evacuate the system. The vacuum pump should run for a minimum of 30 minutes to eliminate all moisture from the system. When the suction gauge reads -93.3 kPa (-700 mmHg, -27.55 inHg) for at least 30 minutes, close all valves, and turn off the vacuum pump.

2.

If the suction gauge dose not reach approximately -93.3 kPa (-700 mmHg, -27.55 inHg) in 15 minutes, there is probably a large leak in the system. Partially charge the system, and check for leaks.