Transmission Cooler Diagnosis
Transmission Fluid CoolerCAUTION: Whenever a transmission has been disassembled to install new parts, all transmission fluid coolers (in tank and auxiliary) and transmission fluid cooler lines must be cleaned and back flushed. Use a suitable torque converter/fluid cooler cleaner.
NOTE: Cleaning and back flushing the transmission fluid cooling system along with following all the normal cleaning and inspection procedures as outlined during disassembly and reassembly will keep contamination from re-entering 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 in use.
Transmission Fluid Cooler Flow Test
NOTE: The transmission linkage/cable adjustment, fluid level and line pressure must be within specification before carrying out this test.
1. Remove fluid level indicator from fluid filler tube.
2. Place funnel in fluid filler tube.
3. Raise the vehicle on a hoist. Place suitable safety stands under the vehicle.
4. Remove the cooler return line (rear fitting) from the fitting on the transmission case.
5. Connect one end of a hose to the cooler return line and route other end of the hose up to a point where it can be inserted into the funnel at the fluid filler tube.
6. Remove the safety stands and lower the vehicle. Insert the end of the hose into the funnel.
7. Start the engine and run it at idle with the transmission in NEUTRAL position.
8. 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 2.37 ml (8 ounces) will be in the measuring container; the test is now complete.
9. If the flow is not liberal, stop the engine. Disconnect the hose from the cooler return line and connect it to the converter outline fitting (front fitting) on the transmission case.
10. Repeat Steps 7 and 8. If flow is now approximately 2.37 ml (8 ounces) in 15 seconds, refer to Transmission Fluid Cooler Back flushing and Cleaning. If the flow is still not approximately 2.37 ml (8 ounces) in 15 seconds, service the pump, main control and/or converter.