Transmission Fluid Cooler

Transmission Fluid Cooler

Special Tool(s):

Material:

Transmission Fluid Cooler Flow Test

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 agents. 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.

CAUTION: The transmission fluid must be at normal operating temperature 85°C - 93°C (185°F - 200°F) to make sure that the cooler bypass is open. The cooler bypass is located in the main control valve body. The transmission fluid at normal operating temperature will be hot.

NOTE: The engine idle, transmission linkage/cable adjustment, fluid level and line pressure must be within specification before carrying out this test. For information on engine idle diagnosis, refer to Computers and Control Systems. For information on fluid level check, refer to Transmission Fluid Level Check. For information on line pressure, refer to Special Testing Procedures. Transmission Fluid Level Check Component Tests and General Diagnostics

1. Place the transmission range selector lever into PARK.
2. Raise the vehicle on a hoist and place suitable safety stands under the vehicle. Refer to Maintenance/Service and Repair.
3. Hold the large drain plug with a wrench, and remove the small (center) fluid level indicating plug using a 3/16-inch Allen key.





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. Remove the safety stands and lower the vehicle.
8. Start the engine and run at idle.
9. With the engine running, raise the vehicle on a hoist and place suitable safety stands under the vehicle. Refer to Maintenance/Service and Repair.
10. Monitor the transmission fluid temperature to make sure that the transmission fluid is at normal operating temperature 85°C - 93°C (185°F - 200°F).
11. 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 was observed, approximately 208 ml (7 oz) will be in the measuring container. The test is complete. Reconnect the cooler line and install the fluid fill plug.
12. 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).
^ Tighten to 40 Nm (30 ft. lbs).





13. Repeat Steps 8 through 11. If flow is now approximately 208 ml (7 oz) in 15 seconds, the cooler lines and auxiliary cooler must be cleaned. Refer to Transmission Fluid Cooler - Backflushing and Cleaning. Carry out this entire test after the backflushing and cleaning procedure. If, after carrying out the backflushing and cleaning procedure, the flow is still not adequate, new cooler lines and/or an auxiliary cooler must be installed. If the flow from the case is still not adequate after the installation of new cooler lines and/or an auxiliary cooler (208 ml [7 oz] in 15 seconds), the pump and/or torque converter may be at fault. Carry out the appropriate procedures for diagnosis and repair.