Transmission Fluid Cooler

Transmission Fluid Cooler

NOTICE: Whenever a transmission has been disassembled to install new parts, the transmission fluid cooler tubes and the in-tank cooler if equipped must be cleaned and backflushed. Use a suitable torque converter/fluid cooler cleaner.

NOTE: If the vehicle is equipped with a oil-to-air (OTA) cooler, a new OTA must be installed.

NOTE: Cleaning and backflushing the transmission fluid cooling system along with following all the normal cleaning and inspection procedures in this section during disassembly and reassembly will keep contamination from reentering the transmission and causing a repeat repair.

When internal wear or damage has occurred in the transmission, 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 transmission troubles and must be removed from the system before the transmission is put back into use.

Transmission Fluid Cooler Flow Test

NOTE: The transmission linkage/cable adjustment, transmission fluid level and line pressure must be within specification before carrying out this test. Refer to Transmission Control Systems for adjustments.

1. Remove transmission fluid level indicator from transmission fluid filler tube.

2. Place funnel in transmission fluid filler tube.

3. Position the vehicle on a hoist.

4. Remove the cooler return tube (top fitting) from the fitting on the transmission case.

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

6. Remove the safety stands and lower the vehicle. Insert end of hose into the funnel.

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

8. When transmission fluid flows from the hose in a steady stream, a liberal amount of transmission fluid should be observed. Liberal is about 1L (1 qt) delivered in 15 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 fitting (bottom fitting) on the transmission case.

10. Repeat Steps 6 and 7. If flow is now approximately 1 L (1 qt) in 15 seconds, refer to Transmission Fluid Cooler Backflushing and Cleaning. If the flow is still not approximately 1 L (1 qt) in 15 seconds, repair or install pump and or converter.

For the installation of new transmission fluid cooler or tubes, refer to Transmission Cooler.

Water in Transmission Fluid

To correctly repair an automatic transmission or transaxle that has had water or coolant introduced into the system, completely disassemble, clean and replace the following parts:

- All internal and external seals

- All friction material; clutches and bands

- Torque converter

- All parts with bonded seals

- All solenoids

- All transmission fluid filters

Prior to installing the transmission or transaxle, the transmission fluid cooler(s), transmission fluid cooler tubes and transmission fluid cooler hoses need to be flushed and cleaned.