Transmission Fluid Cooler
Transmission Fluid Cooler
CAUTION: Whenever a transmission has been disassembled to install new parts or the installation of a new or remanufactured transmission has been installed, new transmission fluid coolers, either in-tank, auxiliary or oil to air (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
NOTE: Cleaning and backflushing the transmission fluid cooling system, along with following all the normal cleaning and inspection procedures 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 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 in use.
When evidence of transmission fluid contamination (for example, metal particles, clutch plate material or band material) is found in the cooling system, the transmission fluid cooler flow test should be carried out.
Transmission Fluid Cooler Flow Test
NOTE: If the transmission fluid cooler fails the transmission fluid cooler flow test, a new transmission fluid cooler should be installed and the fluid cooler tubes should be cleaned and flushed.
NOTE: The following components should be checked and should be within specifications prior to carrying out this test:
^ Engine idle, refer to Computers and Control Systems.
^ Check transmission fluid level, refer to Preliminary Inspection. Preliminary Inspection
^ Line pressure, refer to Special Testing Procedures. Special Testing Procedures
^ Transmission must be at normal operation temperature, 66° C-77° C (150° F-170° F).
1. Remove fluid level indicator from fluid filler tube.
2. Place funnel in fluid filler tube.
3. Position the vehicle on a hoist. Refer to Maintenance/Service and Repair and place suitable safety stands under the vehicle.
4. Prior to carrying out the Transmission Fluid Cooler Flow Test, check to see if the vehicle is equipped with an inline fluid filter. If the vehicle is equipped with an in-line fluid filter it must be removed and discarded prior to carrying out the Transmission Fluid Cooler Flow Test and any system flushing.
5. Remove the cooler return line (top fitting) from the fitting on the transmission case.
6. Connect one end of a hose to the cooler return line 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. Remove the safety stands and lower the vehicle. Insert the end of the hose into the funnel.
8. Start the engine and run it at idle with the transmission in PARK position.
9. Once a steady flow of fluid (without air bubbles) is observed, remove the hose from the funnel and place the hose in a measuring container for 15 seconds. After 15 seconds place the hose back into the funnel and turn the engine off. Measure the amount of fluid in the container. If adequate flow was observed, approximately 322 ml (11 oz) will be in the measuring container; the test is now complete.
10. If the flow is not adequate, 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 (top fitting).
11. Repeat Steps 8-9. If the flow is now approximately 322 ml (11 oz) in 15 seconds, install a new transmission fluid cooler and flush the transmission fluid cooler tubes.
12. If the flow from the case is still not adequate 322 ml (11 oz) in 15 seconds, service the pump, main control and/or torque converter.
13. Once an adequate flow has been established, install a new in-line fluid filter, if previously removed.
Transmission Fluid Cooler Tube
For installation of new fluid cooler tubes, refer to Transmission Cooling.