A/T Oil Cooler - Backflush Alternative
NO: TSB-99-23-011DATE: October, 1999
MODEL: All A/T models
SUBJECT:
OIL COOLER BACKFLUSH ALTERNATIVE
PURPOSE
When repairing or replacing an automatic transmission, be sure to thoroughly flush the A/T oil cooler and verify that the ATF flows through the cooler at a rate of at least one quart in 20 seconds or less. If the oil cooler is not flushed before installing the new A/T unit, the restricted oil cooler could cause severe damage to the transmission.
There are now two accepted methods of backflushing the A/T oil cooler. MMSA's preferred method is to use a flushing tool such as OTC p/n 108-MLS-6906A, available from OTC or DES (call 1-800-727-6672).
However, if a flushing tool is unavailable, an acceptable alternative is to use an aerosol A/T Oil Cooler Flush solution, listed in the PARTS INFORMATION section of this bulletin.
This bulletin describes how to use aerosol A/T Oil Cooler Flush solution as an alternative oil cooler backflushing method when a flushing tool is not available.
AFFECTED VEHICLES
All models equipped with automatic transmission
PROCEDURE
1. Identify the oil cooler inlet and outlet hoses at the transmission. Mark the hoses with tape or parts tags for reassembly. Disconnect the oil cooler lines at the transmission. The following illustrations show the locations of the inlet and outlet hoses for each type of automatic transmission.
IMPORTANT
Follow the manufacturer's safety precautions described on the aerosol can.
2. Insert the nozzle of the aerosol can to the inlet ("to cooler") hose and secure it with a hose clamp. Position the other hose so it drains into a waste container.
3. Hold the can upright. Remove the protective flip cap at the top and press firmly on the button to release the solution.
4. Continue flushing the cooler until only clear liquid comes from the outlet hose.
5. Reverse the hoses and flush in the other direction until only clear liquid comes from the hose. For best results, use the entire contents of the aerosol can.
IMPORTANT
Clear liquid must flow freely in both directions through the oil cooler. If not, the oil cooler is clogged with debris and must be replaced.
6. Turn the can upside down and blow any remaining liquid out of the cooler.
7. Verify that the flushing was adequate by performing the transmission cooler and auxiliary oil cooler flow test described in TSB-98-23-004.
8. Reconnect the cooler hoses to the transmission and secure with clamps. Confirm that the hoses are connected correctly to the inlet and outlet pipes of the transaxle.
8. Start the engine and check for leaks. With the A/T fluid temperature at normal operating temperature (70-90° C or 158-194° F), check the automatic transmission fluid (ATF) level with the engine idling and the transaxle in "Neutral."
9. Add ATF as necessary to bring the ATF level to the top of the "FULL" mark on the A/T dipstick.
10. Dispose of the waste solution in accordance with local, state, and Federal regulations.
PARTS INFORMATION
WARRANTY INFORMATION