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A/C Refrigerant Leak Test

  • Compressed air mixed with the R-134a forms a combustible vapor.
  • The vapor can burn or explode causing serious injury.
  • Never use compressed air to pressure test R-134a service equipment or vehicle air conditioning systems.

  • 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.

Use only service equipment for refrigerant HFC-134a (R-134a).
If accidental system discharge occurs, ventilate the work area before resuming service.
R-134a service equipment or vehicle air conditioning systems should not be pressure tested or leak tested with compressed air.
Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.
  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. Open the high pressure valve to charge the system to the specified capacity, then close the supply valve, and disconnect the charging station fittings.
    Select the appropriate units of measurement for your refrigerant charging station.
    Refrigerant Capacity:
    370 to 420 g
    0.37 to 0.42 kg
    0.82 to 0.93 lbs
    13.1 to 14.8 oz

  1. Check the system for leaks using an R-134a refrigerant leak detector with an accuracy of 14 g (0.5 oz) per year or better.
  1. If you find leaks that require the system to be opened (to repair or replace hoses, fittings, etc.), do a recovery of the system.
  1. After checking and repairing leaks, the system must be evacuated.