{"id":19863,"date":"2025-04-30T05:00:52","date_gmt":"2025-04-30T09:00:52","guid":{"rendered":"https:\/\/gm-techlink.com\/?p=19863"},"modified":"2025-06-17T14:35:42","modified_gmt":"2025-06-17T18:35:42","slug":"keep-your-cool-air-conditioning-refrigerant-leak-diagnostic-tips","status":"publish","type":"post","link":"https:\/\/gm-techlink.com\/?p=19863","title":{"rendered":"Keep Your Cool \u2014 Air Conditioning Refrigerant Leak Diagnostic Tips"},"content":{"rendered":"

All current GM vehicles are manufactured with fluorescent dye installed in the air conditioning refrigerant system. The dye mixes and flows with the A\/C compressor oil to help in locating any leaks in the A\/C system over time. Leaks in the system will be indicated in a light green or yellow color when using the GE-42220 Universal 12V Leak Detection Lamp to check fittings and connections, A\/C components, seals, hoses and other areas.<\/p>\n

Fluorescent dye will assist in locating most medium-to-large leaks in the A\/C system, but to verify some passive leaks, the GE-50078 Electronic Leak Detector or other SAE J2913-certified electronic leak detector may be required. (Fig. 1)<\/p>\n

TIP:<\/strong> Only use a SAE J2913-certified electronic leak detector when checking for leaks in an R-1234yf A\/C refrigerant system.<\/p>\n

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\"\"Fig. 1<\/strong><\/p>\n

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Before replacing any parts in the A\/C system, a thorough diagnostic process following the appropriate Service Information (SI) should be used to identify the root cause of the condition. In a number of recent cases analyzing evaporators returned under warranty, there has been a high rate of No Trouble Found for these components. Following the diagnostics in SI will help prevent the unnecessary replacement of system components.<\/p>\n

Using the Sniffer Probe<\/strong><\/p>\n

When using an electronic leak detector to check the evaporator, the probe should not be placed in the A\/C vents or outlets. (Fig. 2) The outlets are too far from the evaporator to be effective.<\/p>\n

In addition, HVAC module plastics and sealing materials can off-gas hydrocarbons, which may trigger the sniffer alarm. As a result, putting the sniffer probe in an A\/C outlet introduces a high risk for a false trigger where the sniffer says there is a leak but there really is not.<\/p>\n

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\"\"Fig. 2<\/strong><\/p>\n

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In fact, SAE J1628 (Industry Refrigerant Leak Detection Best Practices) and the EPA 609 Certification process suggest using the sniffer probe in the A\/C outlets should be a last resort during diagnosis.<\/p>\n

Instead of inserting the sniffer probe in an A\/C outlet, the probe should be placed within 3\/8-inch of the part, joint, seam, seal, etc., being checked. The electronic leak detector will not be effective if the sensor is not within 3\/8-inch of the component seam, joint, seal or interface being checked.<\/p>\n

Evaporator Leaks<\/strong><\/p>\n

The preferred method for determining if there is an evaporator leak is by checking for the presence of fluorescent dye or excessive compressor oil on the HVAC condensation drain tube.<\/p>\n

When looking at the evaporator during leak diagnosis, focus on the evaporator drain tube using a simple process:<\/p>\n