Fluid Leak Diagnosis
Fluid Leak Diagnosis
General Method
1. Verify that the leak is transmission fluid.
Caution: Do not clean using brake cleaner or other reactive solvents as these solvents can damage rubber gaskets, seals and bushings.
2. Thoroughly clean the suspected leak area using a rag.
3. Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
4. Park the vehicle over clean paper or cardboard.
5. Shut OFF the engine.
6. Look for fluid spots on the paper.
7. Make the necessary repairs.
Powder Method
Caution: Do not clean using brake cleaner or other reactive solvents as these solvents can damage rubber gaskets, seals and bushings.
1. Thoroughly clean the suspected leak area using a rag.
2. Apply an aerosol type leak tracing powder to the suspected leak area.
3. Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
4. Shut OFF the engine.
5. Inspect the suspected leak area.
6. Trace the leak path through the powder in order to find the source of the leak.
7. Make the necessary repairs.
Dye and Black Light Method
A fluid dye and black light kit is available from various tool manufacturers.
1. Follow the manufacturer's instructions in order to determine the amount of dye to use.
2. Operate the vehicle for 24 km (15 mi) or until normal operating temperatures are reached.
3. Detect the leak with the black light.
4. Make the necessary repairs.
Find the Cause of the Leak
Pinpoint the leak and trace the leak back to the source. You must determine the cause of the leak in order to repair the leak properly. For example, if you replace a gasket, but the sealing flange is bent, the new gasket will not repair the leak. You must also repair the bent flange. Before you attempt to repair a leak, check for the following conditions, and make repairs as necessary:
Gaskets
* Fluid level/pressure is too high
* Plugged vent or drain-back holes
* Improperly tightened fasteners
* Dirty or damaged threads
* Warped flanges or sealing surface
* Scratches, burrs, or other damage to the sealing surface
* Damaged or worn gasket
* Cracking or porosity of the component
* Improper sealant used, where applicable
* Incorrect gasket
Seals
* Fluid level/pressure is too high
* Plugged vent or drain-back holes
* Damaged seal bore
* Damaged or worn seal
* Improper installation
* Cracks in component
* Manual shaft or output shaft surface is scratched, nicked, or damaged
* Loose or worn bearing causing excess seal wear
Possible Points of Fluid Leaks
Transmission Case Cover and/or Valve Body Cover
* Incorrectly tightened bolts
* Improperly installed or damaged gasket/seal
* Damaged mounting face
* Incorrect gasket seal
Case Leak
* Damaged input speed sensor seal
* Damaged manual shaft seal
* Loose or damaged oil cooler lines/seals
* Worn or damaged axle shaft oil seal
* Loose line pressure pipe plug or fluid level pipe plug
* Porous casting
* Warped torque dampener housing
* Damaged dampener housing to case seal
Leak at the Torque Dampener End
* Dampener leak in the weld area
* Dampener seal lip cut. Check the dampener hub for damage
* Dampener seal bushing moved forward and damaged
* Dampener seal garter spring missing from the seal
* Porous casting of the torque dampener housing
Leak at the Vent
* Overfilled system
* Water or coolant in the fluid; The fluid will appear milky
* Transmission case porous
* Incorrect fluid level indicator causing an overfilled system
* Plugged vent
Leak Inspection Points
1 - Manual Shift Shaft Seal
2 - A/Trans Fluid Passage Plug
3 - Case Extension Assembly
4 - Auxiliary Pump Press Plug
5 - Control Valve Body Cover Wiring Connector Hole Seal
6 - Drive Motor/Generator Power Inverter Module Cable Assembly Seal - 3 Phase
7 - Fill Hole Plug
8 - Auxiliary Fluid Motor Retainer
9 - Torque Dampener Housing Outer Seal
10 - Wiring Connector Seal
11 - A/Trans Vent Assembly
12 - Front Wheel Drive Shaft Oil Seal Assembly (LHS)
13 - Oil Level Plug
14 - A/Trans Torque Dampener Fluid Seal Assembly
15 - A/Trans Torque Dampener Assembly
16 - Front Wheel Drive Shaft Oil Seal Assembly (RHS)
17 - Control Valve Body Cover Gasket
18 - Transmission Fluid Drain Plug
19 - A/Trans Case Cover Gasket