A proper air test of the CDF drum is demonstrated here. Note that for the sealing sleeve to properly seat, a specific condition must be met.

Yesterday in Chicago's bitter cold, I performed the air test before final assembly of the valve body. As expected, given the temperature, the drum failed to hold pressure. This was not an oversight in procedure, but rather a predictable result of the cost-not really effective engineering employed by GM/Ford, which utilises plastic sealing components sensitive to thermal contraction.

The solution was straightforward: applying gentle heat from an air blower to warm the ATF and the seal itself. This allowed the seal to expand to its intended size and function perfectly.

Some technicians, MAYBE unaware of this thermal phenomenon, might mistakenly condemn a perfectly good drum. Do not be misled. If you encounter this, simply follow the illustrated step: apply moderate heat to the assembly, then re-test. The drum will likely seal as designed.

This was from a 2019 Ford F-150 with only 63,000 miles. Thank you to GM and Ford for putting a lot of bread on the table. As far as I'm concerned, part of that bread also goes to feed my freely enlightened rats.

[Gm-ford venture- lovely] [Gm-ford veture- lovely] [Gm-ford veture- lovely] [Gm-ford veture- lovely] [Gm-ford veture- lovely] [Gm-ford veture- lovely]

Salim Safran
Owner/Engineer
Transmissions 4 Less Co of America
Chicago, Illinois, USA

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