Electronic Leak Detection Method
Tools Required
J 39400 Halogen Leak Detector
Use the electronic leak detector when inspecting the system for refrigeration system leaks. This unit operates on a 12 volt DC. This unit provides an audible signal which increases in frequency when the unit detects a refrigerant leak. Properly calibrate the tool according to instructions. Use the tool at the proper setting for the system that you are testing. The electronic leak detector has the following 3 settings:
| • | R-12 |
| • | R-134a |
| • | Gross leaks -- for isolating very large leaks that are already found at one of the other settings |
The halogen leak detectors are sensitive to windshield washing solution, many solvents, cleaners, and some adhesives. Work on a clean and dry surface. The following joints may all be tested using this detector, each joint being completely circled moving at 1-2 inches per second with the tip of the probe no more than 6 mm (0.25 in) from the surface:
- Inspect the refrigerant pressure sensor.
- Inspect the service valves.
- Inspect the lines.
- Inspect the evaporator inlet/outlet.
- Inspect the accumulator dryer inlet/outlet connections.
- Inspect the compressor rear head.
- Inspect the housing joints.
- A leak is indicated when the audible tone goes from a steady 1-2 clicks per second to a solid alarm. The balance knob should be adjusted frequently in order to maintain the 1-2 clicks per second.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Inspecting the refrigeration system for leaks. | ||||
1 |
Has the leak stopped? | -- | System OK | |
2 |
Has the leak stopped? | -- | System OK | |
3 |
Has the leak stopped? | -- | System OK | |
4 |
Is the alarm solid? | -- | ||
5 | Repair the leak as needed. Has the leak stopped? | -- | System OK | |
6 |
Is the alarm solid? | -- | System OK | |
7 | Repair the leak as needed. Has the leak stopped? | -- | System OK | -- |
Fluorescent Leak Detection Method
Tools Required
| • | J 41447 Florescent Tracer Dye |
| • | J 41436-1 R134a A/C Tracer Dye Injector |
| • | J 28428-E High Intensity Black Light |
Notice: The tracer dye J 41447 was developed for use with the A/C Refrigerant 134a (R-134a) equipped vehicles or with vehicles that have been retrofitted from R-12 to R-134a. Do not use any other tracer dye in the R-134a system. Use of another dye may affect the system reliability and cause premature compressor failure. Use only a 1/4 oz. charge of the dye. Larger amounts may compromise the reliability of the A/C system. After adding the tracer dye, clean the service valves and all affected surfaces of the dye with GM Engine Degreaser GM P/N 1050436 or an equivalent in order to prevent a false diagnosis.
The R-134a refrigerant is different from the R-12 used in the past, and may require additional methods for leak detection. The R-134a molecule is smaller than the R-12 molecule and can leak through smaller openings. R-134a also does not contain chlorine, which was easily detected using a black light. The fluorescent leak detection method is meant to be used in conjunction with the electronic method, and this method will pinpoint smaller leaks. The R-134a takes time to work. Depending on the rate of the leak, the dye may take up to 7 days to become visible.
Liquid Leak Detection/Pressure Testing Methods
Liquid leak detection/pressure testing methods are not recommended for this vehicle. Liquid/bubble leak detectors have very limited usefulness, due to their lack of sensitivity and restricted visibility in today's refrigerant systems.
Service Port Seal/Cap
The primary seal for the service ports is the sealing cap. The cap contains a specially designed O-ring or gasket which provides a leak-free seal. If the cap becomes loose or is missing, or if the wrong cap is used, a loss of refrigerant will result.
