Fluid Leak Diagnosis
Leakage InspectionLeakage at the main control cover gasket often can be stopped by tightening the main control cover bolts to 16 Nm (12 ft. lbs.). If necessary, install a new main control cover gasket.
Check the fluid filler tube connection at the transaxle case. If leakage is found, install a new fluid filler tube grommet.
Check the cooler lines and fittings between the transaxle and the cooler in the radiator for looseness, wear, or damage. If leakage cannot be stopped by tightening a tube nut, install new parts. When fluid is found leaking between the case and the fluid tube connector, check for a missing or damaged O-ring, then tighten the fitting to maximum specification. Do not try to stop the fluid leak by increasing the torque beyond specification. This can cause damage to the case threads. If the leak continues, install a new fluid tube connector and tighten to specification. The same procedure should be followed for fluid leaks between the radiator and the fluid tube connector.
Check the engine coolant in the radiator. If transmission fluid is present in the coolant, the cooler in the radiator is probably leaking.
The cooler can be further checked for leaks by disconnecting the fluid cooler tubes for the fluid tube connectors and applying no more than 345 kPa (50 psi) air pressure to the fluid tube connectors. Remove the radiator cap to relieve the pressure buildup at the exterior of the fluid cooler tank. If the cooler is leaking or will not hold pressure, install a new cooler.
If leakage is found at the manual control lever, install a new manual control lever seal.
Check for fluid leaking from the differential seal. Leakage can result from a damaged seal, missing garter spring or worn front wheel driveshaft and joint. Install a new seal assembly or front wheel driveshaft and joint as necessary.
Check for fluid leaks in the pump to case interface. A leak may be due to a rolled pump lip seal or a damaged seal. Repair the pump assembly.
External Sealing
The CD4E transaxle has the following parts to prevent external fluid leakages:
- Gaskets
- Lip type seals
- O-rings
- Seal rings
External Sealing
Fluid Leakage in Torque Converter Area
Use the following procedures to locate the exact source of leakage in the torque converter area. Leakage at the front of transaxle, as evidenced by fluid around the converter housing, may have several sources. By careful observation, it is possible in many instances to pinpoint the source of the leak before removing the transaxle from the vehicle. The paths, which the fluid can take to reach the bottom of the converter housing, are as follows (numbers on illustration relate to items below):
Leakage Points
1. Fluid leaking by the converter impeller hub seal lip will tend to move along the drive hub and onto the back of the impeller housing. Except in the case of a total seal failure, fluid leakage by the lip of the seal will be deposited on the inside of the converter housing only, near the outside diameter of the housing.
2. Fluid leakage by the outside diameter of the converter impeller hub seal and the case will follow the same path as leaks by the inside diameter of the seal.
3. Fluid leakage from the converter-to-flexplate stud weld will appear at the outside diameter of the torque converter, on the back face of flexplate, and in the converter housing only near the flexplate. If a converter-to-flexplate stud leak is suspected, remove converter and pressure check.
4. Fluid leakage from the pump will flow down the back of the converter housing. Leakage can be from loose or missing pump bolts, a torn or damaged pump-to-case gasket or a worn pump bushing.
5. Engine oil leaks are sometimes incorrectly diagnosed as transaxle pump seal leaks. The following areas of possible leakage should be checked to determine if engine oil leakage is causing the concern.
- Leakage at the valve cover may allow oil to flow over the converter housing or seep down between the converter housing and cylinder block causing oil to be present in or at the bottom of the converter housing.
- Oil plug leaks will allow oil to flow down the rear face of the cylinder block to the converter housing.
- Leakage at the crankshaft seal will work back to the flexplate and then into the converter housing.
Leak Check Test
The following procedures should be used to determine the cause of the leakage before repair is made.
1. Remove the fluid level indicator and note the color of the fluid. Original factory fill fluid is dyed red to aid in determining if leakage is from the engine or transaxle. Unless a considerable amount of makeup fluid has been added or the fluid has been changed, the red color should assist in pinpointing the leak.
2. Remove the converter housing. Clean off any fluid from the top and bottom of the converter housing, front of the case, and rear face of the engine and oil pan. Clean the torque converter area by washing with a suitable nonflammable solvent and blow dry with compressed air.
3. Wash out the converter housing and the front of the flexplate. The converter housing can be washed out using cleaning solvent and a squirt-type oil can. Blow dry all washed areas with compressed air.
4. Start and run the engine until the transaxle reaches normal operating temperature. Observe the back of the block and top of the converter housing for evidence of fluid leakage. Raise the vehicle on a hoist. Run the engine at fast idle, then at engine idle, occasionally shifting to the DRIVE and REVERSE ranges to increase pressure within the transaxle. Observe the front of the flexplate, back of the block (in as far as possible) and inside the converter housing and front of the case. Run the engine until fluid leakage is evident and the source of leakage can be determined.
Leak Check Test With Black Light
Oil-soluble aniline or fluorescent dyes premixed at the rate of 2.5 ml (1/2 teaspoon) of dye powder to 0.23 liter (1/2 pint) of transmission fluid have proven helpful in locating the source of fluid leakage. Such dyes can be used to determine whether an engine oil or transmission fluid leak is present, or if the fluid in the transmission fluid cooler leaks into the engine coolant system. A black light must be used with the fluorescent dye solution.