For 1990-2009 cars

A refrigerant leak test should be performed on the system whenever a leak is suspected due to system indication of low charge or after any service operation which disturbs the components, lines, or connections. Many methods and special tools are available for this purpose; however, no matter which tool is used, care and diligence are the biggest keys to success.

### Electronic Leak Detection Method

#### Tools Required

J 39400 Halogen Leak Detector

Use the electronic leak detector when inspecting for refrigeration system leaks. This unit operates on a 12 volt DC. The leak detector provides an audible signal which increases in frequency when a refrigerant leak is detected. Properly calibrate the tool. Use the tool at the proper setting for the system that you are testing. The electronic leak detector has the following three settings:

• | R-12

• | R-134a

• | Gross leaks

| This setting isolates very large leaks that are found at one of the other settings

The halogen leak detectors are sensitive to windshield washing solution, many solvents and cleaners, and some adhesives. Work on a clean and dry surface. Complete the following actions when you test the joints:

• | Completely circle each joint.

• | Move the tool 25-50 mm (1-2 inch) per second.

• | Ensure that the tip of the probe is no more than 6 mm (0.25 inch) from the surface.

You may use this detector in order to test the following joints:

1. Inspect the refrigerant pressure sensor.
2. Inspect the service valves.
3. Inspect the lines.
4. Inspect the evaporator inlet/outlet.
5. Inspect the accumulator dryer inlet/outlet connections.
6. Inspect the compressor rear head.
7. Inspect the housing joints.
8. A leak is indicated when the audible tone goes from a steady 1-2 clicks per second to a solid alarm. Adjust the balance knob frequently in order to maintain the 1-2 clicks per second.

If a leak is not found, proceed to the Refrigerant Leak Diagnosis table:

#### Refrigerant Leak Diagnosis

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: Inspecting the refrigeration system for leaks.
1 |

1. Inspect the refrigeration system components for proper torque.
2. Tighten the components as needed.

Has the leak stopped?

--

System OK

Go to Step 2

2 |

1. Inspect the O-rings for damage, dirt or lack of lubrication.
2. Replace the O-rings as needed.

Has the leak stopped?

--

System OK

Go to Step 3

3 |

1. Inspect the refrigeration system connections. Refer to Electrical Diagnosis.
2. Repair as needed.

Has the leak stopped?

--

System OK

Go to Step 4

4 |

1. Turn the blower to the highest setting for at least 15 seconds.
2. Wait for 10 minutes.
3. Remove the blower motor resistor. Refer to Blower Motor Resistor Replacement .
4. Insert the probe into the resistor opening.

Is the alarm solid?

--

Go to Step 5

Go to Step 6

5 | Repair the leak as needed. Has the leak stopped? | -- | System OK | Go to Step 6
6 |

1. Blow compressed air behind and in front of the compressor clutch and pulley for at least 15 seconds.
2. Wait 1-2 minutes.
3. Insert the probe behind and in front of the compressor clutch and pulley.

Is the alarm solid?

--

Go to Step 7

System OK

7 | Repair the leak as needed. Has the leak stopped? | -- | System OK | --

### Florescent Leak Detection Method

#### Tools Required

• | Tracer Dye

• | Tracer Dye Injector

• | High Intensity Black Light

The R-134a refrigerant is uniquely 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 is easily detected using the black light. The efflorescence leak detection method is meant to be used in conjunction with the electronic method, and 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

Due to their lack of sensitivity and restricted visibility in today's refrigerant systems, liquid/bubble leak detectors have very limited usefulness. Therefore, the liquid leak detection/pressure testing methods are not recommended for this vehicle.

### 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. Should the cap be loose, missing, or the wrong usage, a loss of refrigerant could result.