Transmission Fluid Cooler Backflushing and Cleaning

5R55S

Transmission Fluid Cooler Backflushing and Cleaning





NOTICE: 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 Oil-To-Air (OTA), if equipped will need to be installed, otherwise transmission damage can occur. Using a suitable torque converter/fluid cooler cleaner, clean and backflush the transmission fluid cooler tubes.

NOTICE: Use only 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.

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.

NOTE: Do not use any solvents while carrying out this procedure. Only use automatic transmission fluid.

1. Conduct transmission fluid cooler backflushing and cleaning with a suitable torque converter/transmission fluid cooler cleaner. Test the equipment to make sure that a vigorous fluid flow is present before proceeding. Install a new system filter if flow is weak or contaminated.

2. Remove and discard the in-line transmission fluid filter, if equipped.





3. To aid in attaching the cleaner to the transmission steel cooler tubes, connect 2 additional rubber hoses to the transmission end of the steel transmission cooler tubes as described.
- Connect the cleaner tank pressure line to the steel transmission cooler return tube (transmission case upper fitting).

- Connect a tank return hose to the steel transmission cooler pressure tube (transmission case lower fitting). Place the outlet end of this hose in the solvent tank reservoir.





4. Turn on the pump and allow the transmission fluid to circulate a minimum of 5 minutes (cycling switch on and off will help dislodge contaminants in the transmission fluid cooler system).

5. Switch off the pump and disconnect the pressure hose from the transmission cooler return tube.

6. Use compressed air to blow out the cooler(s) and tubes (blow air into the transmission cooler return tube) until all the fluid is removed.

7. Remove the rubber return hose from the remaining steel cooler tubes.