WARNING
Never leak test the A/C system with compressed air. A mixture of air and R-134A can become combustible at high pressure. This mixture may result in fire or explosion causing injury and/or property damage.
WARNING
To avoid personal injury and/or vehicle damage, refer to the service precautions at the beginning of this section.
A/C system service requires the use of a manifold gauge set with vacuum pump or a refrigerant recovery/recycling station. The best way to determine if the system has a leak is to evacuate the refrigerant from the vehicle into a refrigerant recovery/recycling station. Once the refrigerant has been recovered the refrigerant recovery/recycling station will pull a vacuum on the system. Isolate the A/C system by closing the valves when the vacuum reaches -26 in. Hg (-88 kPa). A leak free system should be able to hold vacuum for at least 15 minutes or more. If you can not reach the vacuum specified, air is leaking into the system, and the source must be located and repaired.
Leaks will most likely occur at hose fittings and connections. A leak can also occur at the compressor shaft seal at the front of the compressor. The A/C system contains refrigerant oil mixed with refrigerant. Look for oily deposits at hose and pipe connections that indicate a leak. Fluorescent refrigerant system dye can be added to the refrigerant system to assist in refrigerant system leak diagnosis using an ultraviolet black-light.
Use an electronic refrigerant leak detector to validate leaks.
NOTE: Fluorescent refrigerant system dye is added to the refrigerant system at the factory on some vehicles. It is not necessary to add additional dye to the refrigerant system before diagnosing leaks, even if a significant amount of refrigerant has been removed from the system.
| Manifold gauge set components
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| Refrigerant recovery/recycling station
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