The transmission dipstick in my wife's Dart (360/904) leaks like a sieve, we replaced the O-ring twice and it hasn't helped. Could it be something else, or is the ring just misplacing during installation. Has anyone else had this problem and how did you fix it, e.g. some type of sealer on the tube. Thanks for any help, this is driving me nuts.

I grafted on a modern tube end for the transmission and used the new seal instead. it runs up most of the tube that is inserted instead of an o-ring.

I had a pesky one & I dropped the pan cleaned the hole/dipstick end (remove O ring first/clean it too) with brake kleen squeaky clean so the cement would adhere then applied RTV & let it set up good, no more leaking on that one

I did the same as Robert and it worked for me too.

Done this several times. Clean the area around the dipstick tube, make sure all the tranny fluid is cleaned off at the base where the dipstick inserts into the case. Take a cap of DOT 3 and pour it around the base. Let the car sit for a day. Then take it for a drive. Eventually the rubber will swell. I wouldn't do it more than once. If you replace the the o ring rub the o ring in Dot 3and insert the tube. Again let it sit before adding tranny fluids. Has worked for me several times.

I did the same without dropping the pan. Suck out as much fluid as possible from the tube. Raise the front of the car. Remove the tube. Clean every surface, again and again. Install the tube with new oring AND silicone. I know, not normal procedure. Bolt tube to block (yours WAS secured right?). Wait Overnight refill fluid and drive.

If you need a new or a custom tube assembly, contact Dan Masta - very reasonably priced too: http://www.mastaperformance.com/

Dan is a GREAT guy & an old school racer & heavy mechanic. I wouldn't trust many people with an engine, transmission, or rear end as much as I would Dan. Tell him Eric sent you.

Yes. The groove that the O ring sits in is a formed bead, the tube often cracks at the bead especially if the upper bracket isn't attached. Remove the tube and closely inspect the area of the bead...especially above the bead.

I did what robert did. But I remember when searching this problem when it was happening to me I swear some guys talked about using fill tubes from Dakotas that have redesigned technology. My memory isnt that great, but If Im right hopefully some of those guys could chime in

I agree with John, cracked tube end is the first thing to look for. The other is an egg shaped tube - usually done when someone jerks the tube back and forth to get it out - then the o ring is tight at two spots and loose at two spots - like tight at 12 and 6 and loose at 3 and 9 O'Clock. Brake fluid swells the loose spots. We never used any sealer in production - new tube and new seal. No issue until the seal cooked from temperature or age. The sleeve fixed the tube issue as it rode up higher on the tube and no o ring groove plus no egg shapping.

Would this bolt up to an E body?

http://www.manciniracing.com/alpelotrdi.html

Thanks for all the hints everyone, I have a few things to work at now. And yes, it was correctly bolted to the back of the block.

Thanks again, had to replce the tube, it was a bit bent at the bead so it was pinching the O ring. Put it in with a little RTV above the O ring and so far its leak free.