Always conduct a leak test with an electronic leak detector whenever leakage of refrigerant is suspected and when conducting service operations which are accompanied by disassembly or loosening of connection fittings.
In order to use the leak detector properly, read the manual supplied by the manufacturer.
If a gas leak is detected, proceed as follows:
Check the torque on the connection fittings and, if too loose, tighten to the proper torque. Check for gas leakage with a leak detector.
If leakage continues even after the fitting has been tightened, discharge the refrigerant from the system, disconnect the fittings, and check their seating faces for damage. Always replace, even if the damage is slight.
Check the compressor oil and add oil if required.
Charge the system and recheck for gas leaks. If no leaks are found, evacuate and charge the system again.
Fluorescent Dye Leak Detection
General Motors vehicles are now manufactured with fluorescent dye installed directly into the A/C system.
The fluorescent dye mixes and flows with the PAG oil throughout the refrigerant system.
Verifying some passive leaks may require using the Halogen Leak Detector J-39400-A, even though the A/C system contains fluorescent dye.
The only time that adding additional fluorescent dye is required is after flushing the A/C system.
Halogen Leak Detector
Do not operate the detector in a combustible atmosphere since its sensor operates at high temperatures or personal injury and/or damage to the equipment may result.
Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in order to perform a leak test.
Halogen leak detectors are sensitive to windshield washing solutions, many solvents and cleaners, and some adhesives used in the vehicle.
Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.
Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.
Follow the instructions supplied with the Halogen Leak Detector J-39400-A.