For 1990-2009 cars

### General Method

1. Verify that the leak is transmission fluid.
2. Thoroughly clean the suspected leak area.
3. Operate the vehicle for about 15 minutes or until normal operating temperatures are reached.
4. Park the vehicle over clean paper or cardboard.
5. Turn OFF the ignition.
6. Look for fluid spots on the paper.
7. Make the necessary repairs.

### Powder Method

1. Thoroughly clean the suspected leak area with solvent.
2. Apply an aerosol type powder (foot powder) to the suspected leak area.
3. Operate the vehicle for about 15 minutes or until normal operating temperatures are reached.
4. Turn OFF the ignition.
5. Inspect the suspected leak area.
6. Trace the leak path through the powder to find the source.
7. Make the necessary repairs.

### Dye and Black Light Method

1. Follow the manufacturer's recommendation for the amount of dye to be used.
2. Operate the vehicle until the dye can be seen in the leaking fluid.
3. Find the leak with a black light.
4. Make the necessary repairs.

### Gasket and Seal Checks

Once the leak has been pinpointed and traced back to its source, the cause of the leak must be determined in order for it to be repaired properly. If a gasket is replaced, but the sealing flange is bent, the new gasket will not repair the leak. The bent flange must be repaired also before attempting to repair a leak, check to be sure that the following conditions are correct as they may cause a leak.

• | Check the gasket areas for the following conditions that may cause a leak:

- | The fluid level or pressure is too high

- | A plugged vent or drain-back holes

- | Improperly torqued fasteners or dirty/damaged threads

- | Warped flanges or warped sealing surfaces

- | Damaged or worn gaskets

- | Cracking or porosity of the component

- | Improper sealant used (where applicable)

• | Check the seal areas for the following conditions that may cause a leak:

- | The fluid level or pressure is too high

- | A plugged vent or drain-back holes

- | A damaged seal bore (scratched, burred, or nicked)

- | A damaged or worn seal

- | Improper installation

- | Cracks in the component

- | The manual or output shaft surface is scratched, nicked

- | A loose or worn bearing causing excess seal wear

### Possible Points of Oil Leaks

Oil leaks may occur in the following areas:

• | The transmission oil pan or the transmission side cover

- | Attaching bolts that are not tightened to the correct torque specification

- | Improperly installed or damaged gasket

- | Oil pan or mounting face not flat

• | The transmission case

- | The filler tube multi-lip seal damaged or missing

- | The filler tube misaligned

- | The vehicle speed sensor seal damaged

- | The manual shaft seal is damaged

- | The oil cooler connector fittings are loose or damaged

- | The propeller shaft oil seal is worn or damaged

- | The line pressure pipe plug is loose

- | The case casting is porous

• | The converter end seal

- | The seal lip is cut (check the converter hub for damage)

- | The bushing moved forward and is damaged

- | The garter spring is missing from the seal

• | The converter end

- | A converter leak in the weld area

- | A porous casting (case or pump)

• | The vent pipe or the fill tube

- | The transmission fluid level is to high

- | Water or coolant is in the fluid (fluid will appear milky)

- | The case is porous

- | Incorrect fluid level indicator

- | The transmission vent is plugged

- | The drain back holes are plugged

- | Misalignment of the channel plate to case gasket

### Case Porosity Repair

1. Clean the leak area with a solvent and air dry.

Caution: Epoxy adhesive may cause skin irritations and eye damage. Read and follow all information on the container label as provided by the manufacturer.

2. Mix a sufficient amount of epoxy adhesive (GM P/N 1052533 or the equivalent) following the manufacturer's recommendations.
3. While the transmission case is hot, apply epoxy adhesive with a clean, dry soldering acid brush.
4. Allow the epoxy adhesive to cure for 3 hours before starting the engine.
5. Repeat the fluid leak diagnosis procedures.