Use a liquid leak detector solution on locations such as fittings. Apply the solution to the area in question with the swab that is supplied with the solution. Look for bubbles to appear. This will indicate the existence and location of any leak. For areas where this is not practical, such as sections of the evaporator and the condenser, an electronic leak detector is more useful.
Follow the manufacturer's instructions for calibration, operation, and maintenance of an electronic leak detector. Battery condition is especially important to the accuracy of a portable model. Set the detector to R-134a before beginning the test.
Use the following guidelines when using an electronic leak tester:
Follow the entire path of the refrigerant system.
Test all of the following areas, even after 1 leak has been confirmed:
Evaporator inlet and outlet
- The sealing cap is the primary seal for the service ports. This cap contains a special leak-free O-ring. Make sure that this cap is not missing or loose. Always use the correct cap.
Leaks in the evaporator core are difficult to find. Test the evaporator core using the following procedure:
- Run the blower fan at speed setting 4 for at least 15 minutes.
- Turn the blower to the OFF position.
- Wait for 10 minutes.
- Remove the blower motor resistor. Refer to Blower Motor Resistor Replacement .
- Insert the leak detector probe as close as possible to the evaporator core. The detector will indicate a leak with a solid alarm.
- Use a flashlight to search for refrigerant oil in the core surface.
Test the compressor shaft seal using the following procedure:
- Blow shop air behind and in front of the compressor clutch/pulley for at least 15 seconds.
- Wait 1-2 minutes.
- Probe the area in front of the pulley. If the detector emits a solid alarm, there is a leak.