The Stovebolt Site Forums The Shop Area The HiPo Shop Tubro 350 tranny ques.

My friends truck transmission leaks badly if it sits a good while. He wants to install a check valve in the trans. cooler line. But which one? Top or bottom? Anyone know? Thanks

I believe the upper line is the pressure feed to the cooler, but a check valve isn't likely to help. It would be simpler and more effective to drop the valve body and fix it right. There's a "converter anti-drainback valve" that's supposed to keep the converter filled, so a check valve shouldn't be necessary. He can also stop the leak by plugging up the tiny hole in the middle of the driveline slip yoke rear plug. That's where the fluid gets out if the converter drains back into the case.
Jerry

Why not find & fix the leak instead of trying to "fix" sometheing that is most likely not the issue? Common leaks when setting: manual shift shaft seal, speedometer drive.

By any chance, is it leaking out the front seal? Thats real common, when they sit for a long time they tend to leak. Once you start using them they stop leaking.

As was already mentioend, that's because of the anti-drainback valve for the converter. If the valve is working correctly it shouldn't do this.

Unless the seal was faulty or the pump bushing was worn.

Thanks for all the inputs. The leak seem to be everywhere. Now for correct repair. I've searched for repair/replacement information, but found very little. What little I found would indicate the valve is located where the filter attaches to the tranny. Is this correct? Also, if someone knows of a site where this repair is explained I would appreciate the limk. Thanks

could it be the incorrect gasket material. i have better luck with cork gasket. also the oil stick leaked where the pipe went into, went to a tranny shop and he gave me a rubber grommet that went down inot the transmssion and then insert the tube into. and it stop that leak

In the time we've been discussing this leaky 350, it could have been removed, totally sealed, and back in service. There are several possibilities, but the very first thing to do is get it CLEAN, and locate where the leak is actually coming from. Then fix it! Possible problem areas are the manual shift shaft seal, the dipstick/fill tube O ring, the accumulator cover O ring, and the vent hole in the output slip yoke. Obviously, the pan gasket can also leak, plus the front and rear lip seals at the converter and the output yoke.

Grt it completely clean and dry, jack up the rear wheels and put the axles on jack stands, and run it in place until something starts leaking. The other method, hanging onto the undercarriage on a road test, is really not an option!
Jerry

Look here,
http://talk.classicparts.com/showthread.php?t=422

Joe