Leak Testing (HP2)

Leak Testing (HP2)

Special Tools
* GE-50078 - Infrared Refrigerant Leak Detector
* GE-42220 - Universal 12V Leak Detection Lamp
* GE-43872 - Fluorescent Dye Cleaner

For equivalent regional tools. Refer to Special Tools (Heating, Ventilation, and Air Conditioning).

Refrigerant Leak Testing

Note: All A/C system repairs must be verified using electronic leak detection. Dye detection may take up 2 or 3 days to be reliable.

Note: General Motors vehicles are now manufactured with fluorescent dye installed directly into the air conditioning (A/C) system.

The fluorescent dye mixes and flows with the refrigerant oil throughout the refrigerant system.

Verifying some passive leaks may require using the GE-50078 - Infrared Refrigerant Leak Detector , even though the A/C system contains fluorescent dye.

Visual Inspection

Visually trace the entire refrigerant system and look for signs of lubricant leakage, damage, and corrosion on all lines hoses and components (Oil can be an indication of a leak). Each questionable area should be checked for leaks using an electronic leak detector.

Fluorescent Leak Detector

Note: Always use UV protective eyewear when working with UV light.

Fluorescent dye will assist in locating any leaks in the A/C system.

Note: 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 drain.
* Leaks 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:

- All fittings or connections that use seal washers or O-rings
- All of the A/C components
- The A/C compressor shaft seal
- The A/C hoses and pressure switches
- The HVAC module drain tube, if the evaporator core is suspected of leaking
- The service port sealing caps
The sealing cap is the primary seal for the service ports.

* Follow the instructions supplied with the GE-42220 - lamp.
* To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and the approved GE-43872 - cleaner.

Replacing System Dye After Flushing

Note: Do not add dye to the refrigerant system equipped with high voltage electric compressors. The only means of replenishing dye after flushing is by replacing component containing the dye. Currently a compatible dye wafer is contained in the O.E. desiccant package. Adding dye that is not compatible with the high voltage electric compressor may cause compressor damage and high voltage isolation faults.

To prevent false diagnosis, thoroughly clean any residual dye from the service port with a rag and the approved fluorescent dye cleaner GE-43872 - cleaner.

Electronic Leak Detection

Infrared detectors operate differently than heated sensor type detectors. They detect changes in concentration of refrigerant rather than absolute concentration. If the tip is held at a detected leak for more than 5 seconds the detector will saturate and zero to that concentration and will no longer detect leaks at that concentration or less. Move tip away from the leak saturation area for 30 seconds to reset the sensitivity of the detector.

Adequate system pressure is required for effective leak detection.

* If system is empty install 10% of system charge.
* Temperature must be above 60 F.

Do not use:

* Soap solutions (not effective for leak detection)
* Shop air (will introduce contamination to the refrigerant system)
* High pressure gasses i.e nitrogen (May cause system damage

Air movement from the engine cooling fan can affect the detectors ability to detect leaks. Always leak test with engine off and if possible after engine has reached normal operating temperature.

* All fittings and components should be checked.
* Take care not to contaminate the probe tip if the part being tested is contaminated.
* No cleaners containing solvents should be used prior to using electronic leak detector.
* Always follow the refrigerant system around in a continuous path so that no areas of potential leaks are missed. Move the tip along the refrigerant system at a rate of no more than 3 inches per second and a distance of 3/8 inch from the surface being tested. If a leak is found, always continue to test the remainder of the system.

Follow the instructions supplied with the GE-50078 - detector.