Component Tests and General Diagnostics
Transmission Fluid Cooler
Special Tool(s)
Material
CAUTION: Whenever a transmission has been disassembled to install new parts or a new or remanufactured transmission has been installed, a new transmission fluid cooler (either in-tank, auxiliary or OTA) if equipped, will need to be installed. Using a suitable torque converter/fluid cooler cleaner, clean and backflush the transmission fluid cooler tubes.
CAUTION: Use only clean automatic transmission fluid specified for this transmission. Do not use supplemental fluid additives, treatments or cleaning agent. The use of these materials may affect transmission operation and result in internal damage to the transmission
CAUTION: When internal wear or damage has occurred in the transmission, metal particles, clutch plate material, or band material may have been carried into the transmission fluid cooler. These contaminants are a major cause of recurring transmission concerns and must be removed from the system before the transmission is put back into use.
When evidence of transmission fluid contamination (such as metal particles, clutch plate material or band material) is found in the cooling system, the transmission fluid cooler flow test should be carried out.
If the transmission cooling system fails the transmission fluid cooler flow test, install a new transmission fluid cooler and flush out the fluid cooler lines. If installing a new transmission fluid cooler, use only factory approved components.
Transmission Fluid Cooler Flow Test
NOTE: The engine idle, fluid level and line pressure must be within specification before carrying out this test.
1. With the vehicle in PARK position it on a hoist.
2. Prior to carrying out this test check to see if the vehicle is equipped with a in-line fluid filter. If the vehicle is equipped with a in-line fluid filter it must be removed and discarded.
3. Using a 3/16 inch Allen key, hold the large drain plug with a wrench and remove the small (center) fluid level indicating plug.
4. Install the special tool into the pan.
5. Remove the cooler return line (upper line) from the fitting on the transmission case.
6. Connect one end of a clear hose to the cooler return line and route the other end of the hose to the special tool in the pan.
7. Lower the vehicle.
8. Start the engine and run it at idle.
9. With the engine running, the vehicle in PARK position it on a hoist.
10. Once a steady flow of fluid (without air bubbles) is observed, remove the hose from the special tool and place the hose in a measuring container for 15 seconds. After 15 seconds, place the hose back onto the special tool. Lower the vehicle and turn the engine off. Measure the amount of fluid in the container. If adequate flow is observed, approximately 208 ml (7 oz) will be in the measuring container. The test is now complete. Reconnect the cooler line and install the fluid fill plug.
11. If the flow is not liberal, disconnect the hose from the cooler return line and connect the hose to the cooler inlet (lower fitting) on the transmission case. Reconnect the cooler return line to the case (upper fitting).
12. Repeat Steps 10-11. If the flow is not approximately 208 ml (7 oz) in 15 seconds, install a new fluid cooler and flush the fluid cooler tubes. If the flow from the case is still not adequate, repair the main control, pump and or torque converter as required.
13. Once an adequate flow has been established, install a new in-line fluid filter, if previously removed.
14. After all the repairs have been made, carry out the fluid level check.