Diagnosis and Testing - Leak Check

Leak Check

1. 1
   Position the vehicle in NEUTRAL on the hoist.
   REFER TO: Preliminary Inspection (307-01A Automatic Transmission - 10-Speed Automatic Transmission - 10R60, Diagnosis and Testing).
2. 2
   Inspect the gasket and sealing surfaces for leaks.
3. 3
   Trace the transmission fluid leak to its highest point.
4. 4
   Clean the suspected leak area.
5. 5
   Lower the vehicle.
6. 6
   Remove the transmission fluid fill plug or the fluid level indicator.
7. 7
   Add leak detection dye to the transmission fluid. Use 1 fl oz (30 ml) of dye solution for every 4 qt (3.8 L) of transmission fluid.
8. 8
   With the transmission fluid at normal operating temperature, road test the vehicle for at least 1 mile using at least one TCC apply.
9. 9
   Position the vehicle in NEUTRAL on the hoist.
   REFER TO: Preliminary Inspection (307-01A Automatic Transmission - 10-Speed Automatic Transmission - 10R60, Diagnosis and Testing).
10. 10
    If the leak source is obvious, repair as necessary.
11. 11
    After repair, clean the affected area.

Torque Converter Housing Leak

1. 1
   Torque converter housing leaks can originate from several locations. The paths by which transmission fluid reaches the bottom of the torque converter housing are shown in the illustration. The following 6 steps correspond to the numbers in the illustration.
   

   1. A transmission fluid leak past the torque converter hub seal lip will tend to travel along the drive hub and onto the rear of the torque converter. Except in cases of complete seal failure, a transmission fluid leak past the seal lip will be deposited on the inner side of the torque converter housing only, near the outside diameter of the housing.

   2. A transmission fluid leak along the outside diameter of the torque converter hub seal and housing will follow the same path as fluid leaking past the inside diameter of the torque converter hub seal.

   3. A transmission fluid leak from the torque converter cover weld or the torque converter stud-to-flexplate weld will appear on the outside diameter of the torque converter on the rear side of the flexplate and in the converter housing only near the flexplate. If a leak from the converter-to-flexplate stud weld, stud weld, or converter cover is suspected, remove the torque converter and perform a pressure test.

   4. A transmission fluid leak from the bolts inside the torque converter housing will run down the rear of the torque converter housing. The leak may be due to loose or missing bolts.

   5. Engine oil leaking from the rear main seal.

   6. Transmission fluid leaking from the front support cover and seal assembly.
2. 2
   Remove the torque converter.
3. 3
   Using a black light, inspect the torque converter housing. Check for dye traces on the pump bolts, front support cover and seal assembly, and torque converter hub seal. Repair as necessary.
4. 4
   If the leak source is not obvious, continue with this procedure to check the torque converter for leaks.
5. 5
   Place the torque converter in an arbor press. Support the torque converter on the mounting pads.

17. Install the torque converter leak detector (307-421A) into the torque converter hub.

18. Secure the press. Apply sufficient press force to seal the torque converter leak detector (307-421A) into the torque converter hub.

19. Connect the compressed air supply to the torque converter leak detector (307-421A).

20. Apply pressure to the torque converter and check for leaks at the welds and seams of the torque converter hub. Use a soap bubble solution around these areas to assist in diagnosis. If leaks are present, install a new torque converter.

21. Inspect the stud or mounting pad and balance weight for leaks. Inspect the weld seams. Use a soap bubble solution around these areas to help diagnose the leak. If leaks are found, install a new torque converter.

22. After repairing the leak, remove any transmission fluid dye residue from the serviced areas.