Transmission Fluid Cooler

Transmission Fluid Cooler

CAUTION: Whenever a transaxle has been disassembled to install new parts or because the valve body sticks from foreign material, the torque converter and transmission fluid cooler must be cleaned by using a suitable cleaner. Under no circumstances should an attempt be made to clean converters by hand agitation with solvent.

When internal wear or damage has occurred in the transaxle, metal particles, clutch plate material or band material can be carried into the torque converter and transmission fluid cooler. These contaminants are a major cause of recurring transaxle concerns and must be removed from the system before the transaxle is returned for repair.

Transmission Fluid Cooler Flow Test

NOTE: The transaxle linkage adjustment, fluid level and line pressure must be within specification before carrying out this test. Refer to Automatic Transaxle/Transmission External Controls - CD4E for transaxle linkage adjustment procedure. For transmission fluid level checking procedures, refer to Preliminary Inspection. For transaxle line pressure testing, refer to Special Testing Procedures. Preliminary Inspection Component Tests and General Diagnostics

1. Check the transmission fluid level and fill as necessary.
2. Remove the transmission fluid level indicator from fluid filler tube and install funnel in fluid filler tube.
3. With the vehicle in NEUTRAL, position it on a hoist. Refer to Maintenance/Service and Repair. Inspect the transmission fluid cooler lines for damage. Install new transmission fluid cooler lines as needed.
4. Disconnect cooler return line (rear line) by separating the tubing from the cooler line rubber hose.
5. Plug the cooler line to avoid transmission fluid loss.
6. Connect one end of a hose to the cooler return line hose and route the other end of the hose up to a point where it can be inserted into the funnel at the fluid filler tube.
7. Start the engine and run at idle with transaxle in NEUTRAL range until the automatic transmission fluid is warm. Temperature is important to the flow rate measurement. Carry out the Fluid Cooler Flow Test.
^ Option 1: Once fluid flow no longer has air bubbles in it, remove the rubber hose from the funnel and insert it into liter container. After 15 seconds, install the hose into the funnel and measure the amount of automatic transmission fluid in the container. The rate of flow should be approximately 28 - 34 oz (0.83 - 1.0 liter) in 15 seconds.
^ Option 2: Once fluid flow no longer has air bubbles in it, remove the rubber hose from the funnel and insert it into a liter container. As soon as one liter (1.06 quart) is dispensed into the container, install the hose into the funnel. One liter of automatic transmission fluid should flow through the cooling system in approximately 15-17 seconds.
8. Once adequate flow is determined, shut off the engine, remove the extension hose and reassemble the cooler line with the constant tension clamp.
9. If flow is not adequate, stop the engine. Disconnect the hose from the cooler return line and connect it to the converter-out line. If flow is now liberal, carry out backflushing and cleaning procedure. Refer to Transmission Fluid Cooler - Backflushing and Cleaning. Refer to transaxle fluid cooler diagnosis in Transmission Fluid Cooler. If flow is still not liberal, repair the pump or converter.
10. Check the transmission fluid level and adjust as required.

Transmission Fluid Cooler Tube Replacement
When fluid leakage is found at the transmission fluid cooler tubes or installation of new cooler tubes is necessary, refer to Transaxle/Transmission Cooling - CD4E.