A/T - Cooler Flushing and Equipment
9225bmw01
Group 24
Automatic Transmission
Bulletin Number
24 05 92 (3520)
Woodcliff Lake, NJ
February 1992
Product Engineering
SUBJECT:
Transmission Cooler Flushing
MODELS:
Automatic transmission vehicles
Situation:
To avoid the possibility of a repeat transmission failure when performing a repair, the oil cooler and lines should be thoroughly flushed to remove any remaining contamination. If the cooler and lines are not flushed, the contaminated fluid will be cycled back into the transmission where it enters the lubrication circuit unfiltered.
Solution:
The repair manual recommends flushing with ATF, but does not go into detail concerning how this is to be accomplished. Product Engineering has tested and recommends the HECAT MODEL HCF-1 Transmission Oil Cooler Flusher. This tool provides a fast, easy to use method of flushing the cooler and lines.
Ordering
Information:
The Hecat HCF-1 may be purchased through the BMW Service Equipment Program. Orders may be faxed to Bob Lyons @ (201) 930-8401. Additional Information regarding this tool is available from:
Harvey Chambers; Hecat, Inc. (404) 623-8286
Warranty
Information:
Work time for flushing the cooler and lines is included in the labor operation for exchanging a transmission. No additional work time may be claimed for this operation, however, use of the Hecat Flusher will reduce the time needed to perform this operation.
INSTRUCTIONS FOR USE OF HECAT TRANSMISSION OIL COOLER FLUSHER
1. Remove fill cap from flusher and fill with approximately 5 quarts of solvent. Do not overfill, allow a head space on top of solvent level for self-pressurization of flusher. Reinstall fill cap and tighten hand tight. DO NOT USE WRENCH TO TIGHTEN FILL CAP.
CAUTION:
Approved solvents are only those petroleum-based solvents generally used to clean automatic transmission parts (i.e. mineral spirits). DO NOT USE SOLVENTS CONTAINING ACIDS, WATER, GASOLINE, OR ANY CORROSIVE LIQUIDS.
Safety-Kleen is one company offering such a solvent. They also provide for pick-up of used solvent for processing in an environmentally accepted practice. For more information in your area, contact your local Safety-Kleen representative or:
Marshal Wood, 1-800-669-5740 ext. 2592.
2. Shut off both air and solvent valves on flusher. Install quick coupling connector on flusher to match your present shop air supply. Couple shop air supply hose to flusher with quick coupler.
3. Clean fitting on vehicle oil cooler lines and connect the appropriate line adapters furnished with the flusher. These adapters are designed to attach at the transmission end of the oil cooler lines.
No additional O-rings or seals should be required; however, new O-ring seals should be used on the lines when reinstalling the transmission as the old O-rings may have been damaged by the flusher line adapters.
When installing the hollow bolt type adapters to the banjo eyes on the cooler lines, sealing washers are to be used on both sides of the banjo eye. Tightening of the adapter with wrenches will be required to effect a tight seal between the adapter and the banjo eye. Failure to use the sealing washers could result in possible damage to the sealing surface on the banjo eye.
For optimum cleaning of the cooler and lines, it is required that the initial flushing procedure be carried out against the normal flow of transmission fluid through the cooler. The chart lists the ncessary connections for initial back-flushing of the cooler and lines.
Suspend or place muffler assembly on return hose in a suitable container (i.e. 5 gallon pail). DO NOT SUBMERGE MUFFLER IN LIQUID. This will result in solvent blowing out of the container.
4. Open air valve slightly and observe for movement of air and oil through return hose and muffler.
CAUTION:
If no flow is observed or if pressure relief valve on flusher begins to vent air pressure, shut off air valve immediately and slowly loosen fittings to allow system to depressurize. Correct blockage in transmission cooler or lines before proceeding.
If oil flow is observed from return line, open solvent valve on flusher completely to allow full flow of solvent. Allow solvent to flow until return hose appears clean.
5. Shut off air and solvent valves on flusher, reverse connections of flusher at cooler lines and repeat flushing procedure. When system is thoroughly cleaned, shut off solvent valve. Air valve should be left on until solvent is purged from oil cooler and lines.
6. Shut off air valve and disconnect air supply hose from quick coupler on flusher. No further purging of system is required as solvent has been adequately removed from the system.