A/T Cooler - Flushing Procedure

89Chrysler08

Models

All Domestic Vehicles with Automatic Transmission Coolers


Subject

Transmission Cooler Flushing Procedure


Index

TRANSMISSION


Date

June 5, 1989


No.

21-10-89 REVISION A


P-2170 (C21-12-9)
BODY CODE LEGEND

ALL DOMESTIC CHRYSLER/PLYMOUTH & DODGE VEHICLES


THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN # 21-10-89, DATE 04/24/89, WHICH SHOULD BE REMOVED FROM YOUR FILE. THIS REVISION CORRECTS AN ERROR IN THE A-6Q4 ILLUSTRATION.


SYMPTOM/CONDITION

Repeated automatic transmission failures.


REPAIR PROCEDURE

The purpose of this bulletin is to emphasize the importance of properly flushing the transmission oil cooler following any repair which requires the removal or replacement of any automatic transmission or transaxle. Clogged or restricted transmission oil coolers can be a cause of recurring transmission failures. Restriction of cooler flow can cause overheating of the transmission fluid and reduce important lubrication to internal rotating parts.

Although several styles of transmission coolers are in use, including various oil-to-air designs and those internal to the radiator tank, all have small internal passages which can trap debris, such as loose lock-up clutch friction material and become clogged. It is absolutely necessary, in any case of transmission failure, to thoroughly flush the cooler, following the procedure outlined below and then check the flow to ensure that all possible debris has been removed.

When reverse flushing an automatic transmission cooler the following procedure should be used:

FIGURE 1 - A604 TRANSAXLE:

FIGURE 2 - A413/A670 TRANSAXLE:

FIGURE 3 - REAR WHEEL DRIVE TRANSMISSION:

1. Identify the To Cooler and From Cooler lines from the accompanying figures.

2. Disconnect the cooler lines at the transmission.

3. Using a hand suction gun filled with mineral spirits, reverse flush the cooler by forcing mineral spirits into the From Cooler line of the cooler and catching the exiting spirits from the To Cooler line. Observe for the presence of debris in the exiting fluid. Continue until fluid exiting is clear and free from debris.


NOTE: IF AT ALL POSSIBLE, THE COOLER SHOULD BE REMOVED FROM THE VEHICLE AND THE CLEANING DONE USING A PRESSURE TYPE PARTS CLEANER.


4. Using compressed air in intermittent spurts, blow any remaining mineral spirits from the cooler, again in the reverse direction.

5. To remove any remaining mineral spirits from the cooler, one (1) quart of ATF should be pumped through the cooler prior to reconnecting the hoses to the transmission.

6. If at any stage of the cleaning process, the cooler does not freely pass fluid, the cooler must be replaced.


After the new or repaired transmission has been installed and filled to the proper level with ATF, the flow should be checked using the following procedure:

1. Disconnect the From Cooler line at the transmission and place a collecting container under the disconnected line.

2. Run the engine at curb idle speed, with the shift selector in neutral.

3. If the fluid flow is intermittent or it takes more than 20 seconds to collect one quart of ATF, the cooler should be replaced.


CAUTION: WITH THE FLUID SET AT THE PROPER LEVEL, FLUID COLLECTION SHOULD NOT EXCEED (1) QUART OR INTERNAL DAMAGE TO THE TRANSMISSION MAY OCCUR.


4. If flow is found to be within acceptable limits, reconnect the cooler line and fill transmission to the proper level, using the approved type of ATF.