Transmission Cooler: Testing and Inspection

Transmission Fluid Cooler





Transaxle Cooling









When internal wear or damage has occurred in the transaxle, metal particles, clutch plate material or band material may have been carried into the torque converter and transmission fluid cooler. These contaminants are a major cause of recurring transaxle troubles and must be removed from the system before the transaxle is put back into use. Refer to Transmission Fluid Cooler Backflushing and Cleaning .

Transmission Fluid Cooler Flow Test

NOTE: The selector lever linkage, selector lever cable adjustment, transmission fluid level and line pressure must be within specification before carrying out this test. for selector lever linkage and selector lever cable adjustment and refer to Special Testing Procedures Automatic Transmission - 6F50/6F55 for line pressure test. The transmission fluid must be above 82°C (180°F) for the cooler bypass to open to carry out this test.

1. Using a scan tool, run the engine to establish the correct transmission fluid temperature of 82°C (180°F).

2. Remove the transmission fluid level indicator from the transmission fluid filler tube.

3. Place funnel in the transmission fluid filler tube.

4. With the vehicle in NEUTRAL, position it on a hoist.

5. Remove the transmission fluid cooler return tube (rear fitting) from the fitting on the transaxle case.

6. Connect one end of a hose to the cooler return tube and route other end of the hose up to a point where it can be inserted into the funnel at the transmission fluid filler tube.

7. Start the engine and run it at idle with the transmission in NEUTRAL position.

8. When transmission fluid flowing from hose is in a steady stream, a liberal amount of transmission fluid should be observed. "Liberal" is described as about 1L (1 qt) delivered in 30 seconds. If a liberal flow is observed, the test is complete.

9. If the flow is not liberal, stop the engine. Disconnect the hose from the cooler return tube and connect it to the converter outlet tube fitting (front fitting) on the transaxle case.

10. Repeat Steps 7 and 8. If flow is now approximately 1L (1 qt) in 30 seconds, refer to Transmission Fluid Cooler Backflushing and Cleaning . If the flow is still not approximately 1L (1 qt) in 30 seconds, repair the pump and/or the torque converter.
If new transmission fluid cooler tubes need to be installed, refer to Transmission Cooler, A/T.