A/C System Leak Tests

WARNING: REVIEW THE WARNINGS AND CAUTIONS IN THE GENERAL INFORMATION BEFORE LEAK TESTING THE SYSTEM.

If the air conditioning system does not cool properly, the A/C system performance should be tested. See A/C Performance in the Diagnosis and Testing for the procedures. If the A/C system refrigerant fill is found to be low or if the system is empty; a leak at a refrigerant line, connector fitting, component, or component seal is likely

An electronic leak detector designed for R-134a refrigerant, or a fluorescent R-134a leak detection dye and a black light are recommended for locating and confirming refrigerant system leaks. Refer to the operating instructions supplied by the equipment manufacturer for the proper care and use of this equipment.

An oily residue on or near refrigerant system lines connector fittings, components, or component seals can indicate the general location of a possible refrigerant leak. However, the exact leak location should be confirmed with an electronic leak detector prior to component repair or replacement.

To detect a leak in the refrigerant system with an electronic leak detector, perform one of the following procedures:

System Empty
1. Evacuate the refrigerant system. See Refrigerant System Evacuate in the Service Procedures.
2. Connect and dispense 0.283 kilograms (0.625 pounds or 10 ounces) of R-134a refrigerant into the evacuated refrigerant system. See Refrigerant System Charge in the Service Procedures.
3. Position the vehicle in a wind-free work area. This will aid in detecting small leaks.
4. With the engine not running, use a electronic R-134a leak detector and search for leaks. Because R-134a refrigerant is heavier than air, the leak detector probe should be moved slowly along the bottom side of all refrigerant lines, connector fittings and components.
5. To inspect the evaporator coil for leaks, insert the electronic leak detector probe into the center instrument panel outlet and the floor duct outlet. To inspect the combination coil for leaks, insert the electronic leak detector probe into the overhead duct outlet nearest to where the vertical duct joins the headliner. Set the front or rear blower motor switch to the lowest speed position, and the mode control switch in the recirculation mode (Max-A/C).

System Low
1. Position the vehicle in a wind-free work area. This will aid in detecting small leaks.
2. Bring the refrigerant system up to operating temperature and pressure. This is done by allowing the engine to run with the air conditioning system turned on for five minutes.
3. With the engine not running, use a electronic R-134a leak detector and search for leaks. Because R-134a refrigerant is heavier than air, the leak detector probe should be moved slowly along the bottom side of all refrigerant lines, connector fittings and components.
4. To inspect the evaporator coil for leaks, insert the electronic leak detector probe into the center instrument panel outlet and the floor duct outlet. To inspect the combination coil for leaks, insert the electronic leak detector probe into the overhead duct outlet nearest to where the vertical duct joins the headliner. Set the front or rear blower motor switch to the lowest speed position, and the mode control switch in the recirculation mode (Max-A/C).