93 Auto Trans. Cooler Check Valve

[JDancoe]

On a 1993 D-350 Diesel w/ auto trans. there is a check valve mounted in the line from the transmission cooler output to the engine mounted transmission cooler. It is a piece of hose about (6+" long) with a 1/2" Female flare fitting which screws to the rear cooler fitting on one end, and a fitting with a check valve & !/2" male flare fitting on the other. It appears to have a Mopar P/N: 52028675C.



It's not shown or mentioned in the factory service manual I have, (1992) nor is it shown in the parts book trans. cooler line breakdown. Anyone know why it's there and what purpose it serves? Jack Dancoe

 

[PToombs]

It's there to keep the converter full. It prevents drain back. Some guys remove them because if they get real hot they can stick closed and cook the trans. If they remove it then they have to put it in neutral and wait several seconds for the converter to fill before they drive off.