Before beginning this procedure, refer to the Precautions at the beginning of this section. Only a MVAC-trained, EPA-certified, automotive technician should service the A/C system or its components.
General Motors vehicles are currently manufactured with fluorescent dye installed directly into the Air Conditioning (A/C) system.
The fluorescent dye mixes and flows with the PAG oil throughout the refrigerant systemVerifying some passive leaks may require using the Halogen Leak Detector J 39400-A, even though the A/C system contains fluorescent dyeThe only time that adding additional fluorescent dye is required is after flushing the A/C systemFluorescent dye will assist in locating any leaks in the A/C system
PAG oil is water soluble.
Condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the HVAC module drainLeaks in the A/C system will be indicated in a light green or yellow color when using the leak detection lamp
Use the leak detection lamp in the following areas:
NOTETo prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a clean rag and the approved J 43872.
All fittings or connections that use seal washers or O-rings
If necessary, inject fluorescent dye into the A/C system that is approved by General Motors:
WARNINGNot all of the fluorescent dyes are compatible with PAG oil. Some types of dye decrease the oil viscosity or may chemically react with the oil.
NOTER-134A leak detection dye requires time to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days.
WARNINGDo NOT overcharge the A/C system with dye. Use only one 0.25 oz (7.39 ml) charge.
J 41447 can be poured directly into a removed A/C component
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 1 lb. (0.45 kg) 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 detectorFollow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaksFollow the instructions supplied with the Halogen Leak Detector J 39400-A