Montana, Silhouette, Venture 2000-2005

Testing The System


Leak Testing

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 polyalkylene glycol (PAG) oil throughout the refrigerant system.

Verifying some passive leaks may require using Special Tool J 39400-A Halogen Leak Detector, even though the A/C system contains fluorescent dye. The only time that adding additional fluorescent dye is required would be after flushing the A/C system.

Follows any instruction supplied with a universal leak detection lamp. Leaks in the A/C system will be indicated in a light green or yellow color when using the lamp.

  1. 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.)