For 1990-2009 cars

### Electronic Leak Detection Method

#### Tools Required

J 39400 Halogen Leak Detector

Use the J 39400 when testing for refrigeration system leaks. This unit operates on a 12 volt DC and provides an audible signal which increases in frequency when a refrigerant leak is detected. Properly calibrate the tool to the instructions and use at the proper setting for the system being tested. The J 39400 has the following three settings:

• | R-12

• | R-134a

• | Gross leaks -- for isolating very large leaks already found at one of the other settings

The J 39400 is sensitive to windshield washing solution, many solvents and cleaners, and some adhesives. Work on a clean and dry surface. The following connections may all be tested using this detector, each connection being completely circled moving at 20-50 mm (1-2 inches) per second with the tip of the probe no more than 6 mm (0.25 in) from the surface:

1. Test the refrigerant pressure sensor.
2. Test the service valves.
3. Test the entire length of the hoses or tubes.
4. Test the evaporator core hose or tube connections.
5. Test the compressor rear head.
6. Test the compressor hose assembly connections.
7. Test the accumulator connections.
8. 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.

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

#### Refrigerant Leak Diagnosis

Step | Action | Yes | No
--- | --- | --- | ---
DEFINITION: Inspecting the refrigeration system for leaks using the J 39400
1 |

1. Test the refrigeration system hose and tube connections for the proper torque. Refer to Fastener Tightening Specifications .
2. Tighten the component connections as needed.

Did you find and repair the condition?

System OK

Go to Step 2

2 |

1. Disassemble the leaking connection. Refer to the following:

• | Compressor Hose Assembly Replacement

• | Air Conditioning Evaporator Hose Assembly Replacement

2. Inspect the O-rings for damage, dirt or lack of lubrication.
3. Replace the O-rings as needed. Refer to O-Ring Replacement .

Did you find and repair the condition?

System OK

Go to Step 3

3 | Test the condenser for leaks at the following areas:

• | Front of the condenser for damage

• | Condenser tube welded areas

Did you find a leak?

Go to Step 4

Go to Step 5

4 | Replace the condenser. Refer to Condenser Replacement . Did you complete the repair? | Go to Step 9 | --
5 | Test the compressor seal for leaks using the following procedure:

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.

Does the leak detector indicate a leak?

Go to Step 6

Go to Step 7

6 | Replace the compressor seal. Refer to Compressor Shaft Seal Removal and Compressor Shaft Seal Install . Did you complete the repair? | Go to Step 9 | --
7 | Test the evaporator for leaks using the following procedure:

1. Operate the blower motor on HIGH for at least 15 seconds.
2. Wait 10 minutes.
3. Remove the blower motor resister. Refer to Blower Motor Resistor Replacement .
4. Insert the probe in the blower resister opening.

Does the leak detector indicate a leak

Go to Step 8

Go to Step 9

8 | Replace the evaporator core. Refer to Air Conditioning Evaporator Core Replacement . Did you complete the repair? | Go to Step 9 | --
9 | Test for proper system performance. Refer to VDOT Air Conditioning (A/C) System Diagnosis . Does the system operate correctly and no further system leaks are indicated? | System OK | Go to Florescent Leak Detection Method

### Florescent Leak Detection Method

#### Tools Required

• | J 41447 Fluorescent Tracer Dye

• | J 41436-1 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.

### 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.