Empty Refrigerant System Leak Test

WARNING: R-134a service equipment or vehicle A/C system should not be pressure tested or leak tested with compressed air. Some mixtures of air/R-134a have been shown to be combustible at elevated pressures. These mixtures are potentially dangerous and may result in fire or explosion causing injury or property damage.

CHARGE DETERMINATION
If the A/C system is not cooling properly, determine if the refrigerant system is fully charged with R-134a. This is accomplished by performing a system Charge Level-Check or Fill. if while performing this test A/C liquid line pressure is less than 207 kPa (30 psi) proceed to Empty Refrigerant System Leak Test. if liquid line pressure is greater than 207 kPa (30 psi) proceed to low refrigerant level leak test. if the refrigerant system is empty or low in refrigerant charge, a leak at any line fitting or component seal is likely. A review of the fittings, lines and components for oily residue is an indication of the leak location. To detect a leak in the refrigerant system, perform one of the following procedures as indicated by the symptoms.

WARNING: Avoid breathing A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose and throat. Use only approved service equipment meeting SAE requirements to discharge R-134a system. If accidental system discharge occurs, ventilate work area before resuming service.

EMPTY SYSTEM
1. Evacuate the refrigerant system to the lowest degree of vacuum possible (about 28 in Hg.). Determine if the system holds a vacuum for 15 minutes. if vacuum is held, a leak is probably not present. if system will not maintain vacuum level, proceed with this procedure.
2. Prepare a 0.284 Kg. (10 oz.) refrigerant charge to be injected into the system.
3. Connect and dispense 0.284 Kg. (10 oz.) of refrigerant into the evacuated refrigerant system.
4. Proceed to step two of Low Refrigerant Level Leak Test.