Transmission Fluid Cooler Tubes Backflushing and Cleaning

Transmission Fluid Cooler Tubes Backflushing and Cleaning

1. WARNING: If equipped with fire suppression system, depower the system. For important safety warnings and procedures, refer to Fire Suppression System.

With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Maintenance/Service and Repair.

2. CAUTION: When internal wear/damage occurs in the transmission, metal particles, clutch plate material and band material can travel into the torque converter, the fluid cooler tubes and the oil-to-air (OTA) fluid cooler. These contaminates are a major cause of recurring transmission concerns. To prevent future concerns, remove these contaminants from the cooling system before placing the transmission back into use.

CAUTION: The OTA fluid cooler is not repairable with existing equipment due to the thermostatic bypass valve. Do not attempt to backflush and clean the OTA fluid cooler. Install a new OTA fluid cooler if there is leakage from the OTA fluid cooler, major metallic failure, multiple clutch or clutch plate failure, or sufficient component wear that result in metallic contamination.

Using a suitable torque converter/fluid cooler cleaner, clean the fluid cooler tubes.
3. Test your equipment to make sure that a vigorous fluid flow is present before proceeding. Install a new filter in the flush equipment if the flow is weak or contaminated.
4. 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 follows:
^ Disconnect the fluid cooler tubes from the oil-to-air (OTA) cooler.
^ Install a rubber hose in place of the oil-to-air cooler.
^ Connect the cleaner tank pressure line to the steel transmission cooler return tube (the longest tube).
^ Connect a tank return hose to the steel transmission cooler pressure tube (shorter tube). Place the outlet end of this hose in the fluid tank reservoir.

5. Turn on the pump and allow the fluid to circulate a minimum of 5 minutes (cycling switch ON and OFF will help dislodge contaminants in the cooler system).
6. Switch OFF the pump and disconnect the pressure hose from the transmission cooler return tube.
7. Use compressed air to blow out the cooler(s) and tubes (blow air into the transmission cooler return tube) until all fluid is removed.
8. Remove the rubber return hose from the remaining steel cooler tube.
9. Connect the oil-to-air (OTA) cooler tubes.

10. CAUTION: Contamination can become trapped in the coolers. Clean fluid flow after flushing does not always indicate all contamination has been removed.

Install a new OTA.

11. WARNING: If equipped with fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System.

If equipped with fire suppression system, repower the system.