Leakage Inspection
Leakage InspectionSpecial Tool(s):
Material:
CAUTION: Do not try to stop the fluid leak by increasing the torque beyond specifications. This may cause damage to the case threads.
Leakage at the transaxle pan-to-case gasket often can be stopped by tightening the attaching bolts to 11 Nm (8 ft. lbs.). If necessary, install a new pan case gasket.
Check the fluid tubes and fittings between the transaxle and the auxiliary cooler. If leakage cannot be stopped by tightening the clamps or the cooler tube retainer, install new parts. When fluid is found leaking between the transaxle case and the cooler tube fittings, check for a missing or damaged O-ring seal, then tighten the fitting to maximum specification.
If the leak continues, install new fluid cooler tubes.
If leakage is found at the manual control lever, install a new seal.
If leakage is found at the transaxle internal harness connector, install a new O-rings.
Fluid Leakage in Torque Converter Area
In diagnosing and correcting fluid leaks in the torque converter area, use these procedures to locate the exact cause of the leakage. Leakage at the front of the transaxle, as evidenced by fluid around the torque 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 takes to reach the bottom of the torque converter housing are shown in the illustration. The next 5 steps correspond with the numbers in the illustration.
1. Fluid leaking by the converter hub seal lip will tend to move along the drive hub and onto the back of the torque converter. 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 torque converter housing only, near the outside diameter of the housing.
2. Fluid leakage by the outside diameter of the converter hub seal and the case will follow the same path that leaks by the inside diameter of the converter hub seal follow.
3. Fluid leakage from the converter cover weld or the converter-to-flexplate stud weld will appear at the outside diameter of the torque converter on the back face of the flexplate and in the converter housing only near the flexplate. If a converter-to-flexplate stud or converter cover weld leak is suspected, install a new torque converter.
4. Fluid leaking from the pump cover, pump cover bolts or the torque converter hub seal inside the converter housing will flow down the back of the torque converter housing. Leakage may be from loose or missing pump cover bolts, defective pump cover seal or defective torque converter hub seal.
5. Engine oil leaks are sometimes incorrectly diagnosed as transaxle converter hub seal leaks. These areas of possible leakage should also be checked to determine if engine oil leakage is causing the concern.
1 Leakage at the valve cover gasket may allow oil to flow over the torque converter housing or seep down between the torque converter housing and cylinder block, causing oil to be present in or at the bottom of the torque converter housing.
2 Oil galley plug leaks will allow oil to flow down the rear face of the cylinder block to the bottom of the torque converter housing.
3 Leakage at the crankshaft rear oil seal will work back to the flexplate and then into the torque converter housing.
4 Leakage at the oil pressure sensor.
5 Cracks in the block.
6 Leakage from the engine oil pan.
Leak Check Test
1. Remove the fluid level indicator and note the color of the fluid. Original factory fill fluid is bluish green when new and will darken to dark green or brown as it ages. Unless a considerable amount of makeup fluid has been added or the fluid has been changed, the blue color should assist in pinpointing the leak.
2. Clean off any fluid from the top and bottom of the torque 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 torque converter housing and the front of the flexplate. The torque converter housing may be washed out using cleaning solvent and a squirt-type oil can. Blow all washed areas dry with compressed air.
4. Start and run the engine until the transaxle reaches its normal operating temperature. Observe the back of the cylinder block and top of the torque converter housing for evidence of fluid leakage. Raise the vehicle on a hoist and 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 cylinder block (in as far as possible), and inside the torque converter housing and front of the case. Run the engine until fluid leakage is evident and the probable source of leakage can be determined.
Leak Check Test With A Black Light
UV Fluorescent Tracer Dye (164-R3706 or equivalent specifically formulated for ATF) is used to detect a transmission fluid leak.
1. Add UV Fluorescent Tracer Dye to the transmission fluid. Use one 30.0 ml. (1 oz.) of dye solution for every 3.8 L (4 quarts) of transmission fluid.
2. Start and run the engine until the transaxle reaches its normal operating temperature 90°C (194°F). Observe the back of the cylinder block and top of the torque converter housing for evidence of fluid leakage. Raise the vehicle on a hoist and 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 cylinder block (in as far as possible), and inside the torque converter housing and front of the case. Continue running the engine until fluid leakage is evident and the probable source of leakage can be determined.