Thread: 4T65E Check Valve Fitting

Hi all,

So I got a jy cooler for my 4T65E in my 2004 Impala. The rubber parts of the factory trans cooling lines are dry rotted pretty bad, so I felt it best to install barb fittings and run new hose to the cooler rather than splicing.
Found that there was a check valve in one of the transmission fittings.

It was my understanding that the check valve is internal to the transmission on 2004 and later models. I also found that once I removed the fitting, a bit of fluid came out, but the transmission did not continue to drain fluid from the hole where the fitting was. Maybe my transmission ALSO has the check valve in the channel plate, and I don't need the check valve fitting?

Both fittings use the GM quick disconnects on the line side. I kept the factory lines in place (just disconnected from trans) so I can put everything back if need be, and try something else.

Can someone chime in and give me some direction?

Man there is a thread somewhere that described which years came with what. I'll try and find it

Once the check valve was in the fitting, it would not also have the check ball in the valve body.

Originally Posted by BillBoost37

Once the check valve was in the fitting, it would not also have the check ball in the valve body.

Thanks Bill... how critical is this check valve, btw? I guess it keeps the torque converter from draining back into the pan... why is this necessary?

it's necessary.. I don't recall what it does. Search on Trans info and my name. The answer is in links there