I had this happen. Mine was a twisted O ring on the dip stick tube. I also added washers since the supplied bolts were too long and bottomed out before getting tight. I verified this with the pan off and measuring the installed length. I hope yours turs out this simplke. Mark

 

Mark, I'm pretty sure my pan is getting tight. It leaked with the factory steel pan also. Did your dipstick tube leak without running the car? Were you able to see the leak or did you just take a chance and replace the o-ring?

 

I bought a trans with low miles and it leaked. It was one of those OH NO! moments. Yes it leaked standing still. That threw me off since I didn't think the fluid went that high. I actually bought the o ring at my local hardware store. Maybe not a good idea but it is not leaking 1 year later.

 

A cheap fix for a leaking dipstick is to pull it out, remove the o-ring, clean it and the tube with good solvent or laquer thinner and then coat the o-ring with Lock-tite's Gasket Maker. just a thin film is all that is necessary. Install the o-ring and put a thin film around the assembly. Put it back together -no leak.

 

Could it be leakin from where the kickdown lever connects at the shift lever? I had my kickdown lever off for quite some time, and it was leaking pretty bad.. driven or not. Put a new o-ring and bolted the lever on and the majority of the leak has stopped. I still have a small drip, that could be either the dipstick tube as suggested, or perhaps I have the wrong o-ring installed behind the kickdown lever.

Mike

 

The kick-down shaft can be sealed with a Quad-ring in place of the o-ring for a better seal. Always be sure to lubricate the seal with Vaseline before you install it.

 

There are no leaks down either side of the case that I can see. It has to be either the pan gasket, front pump seal or the dipstick tube. The worst of these would be the pump seal to replace. I would like to know if it would leak just sitting, without starting the motor from the pump seal. I'll remove the dipstick tube today and check it out.

 

The pump seal is not likely to leak while the engine is off. It will leak withthe engine on and then drip after it is shut off. It would drip out the front bottom of the bell housing though and is less likely to be around the pan area.

 

Paul, thanks for the fyi. I'm hoping it's the dipstick tube then. If it is the tube leaking, it is a very deceptive leak. Just looking at it, you would think it's the pan gasket. I'll let ya'll know if and when I finally get it fixed.
Ross

 

I've seen front seals leak all the time bro... Not the front pump seal, but the torque convertor seal...

My 74 Mustang with the C3 in it leaked while not running but didn't leak while running... It was the seal around the convertor snout...

 

Really??????? The pump seal and converter seal is the same thing.. As mentioned already though if it leaks it comes out the bell not at the pan gasket..

 

My c4 had 6 bolts holding the front pump housing to the front of the tranny in my 66 mustang.. It leaked from THAT seal, to me that's the pump seal...
Here is a pic of the front pump on the C4 I did... Maybe they don't have this style anymore, maybe they do I dunno...

The convertor snout seal AND the pump seal both can leak...
I just refer to them separately, but my terminology is probably screwed up

FE

 

dang -- when was the last time you shoveled that garage out -- ???

 

Well in that case it is the pump GASKET...... And the pump needs 7 bolts..

 

Update on leaking C4

Well, I replaced the dipstick tube o-ring and filled her back up with ATF. It doesn't leak as bad, but now it appears to be coming from between the case and the bellhousing. Obviously, the trans will have to come out, but should the pump have to be removed? Thanks

 

Re: Update on leaking C4

If it is leaking between the bellhousing and the main case then it would have to be the pump gasket, loose bolts or stripped threads on the pump /bellhousing bolts. If it is the gasket or stripped threads then yes the pump will have to be removed.

 

I have the same problem with my C6. I think it's becasue my mechanic suggested a power flush (never again) when I had him change the A/T fluid last year. A few weeks later, leaks near the bottom of the dipstick tube. Had that fixed. Few weeks later. Small leak near the kick down lever. I fixed that leak myself. Now it's leaking behind the neutral switch. Have to wait till spring for that job. Anyone has any suggestions on fixing a leak around switch?

 

Anything that has threads, a flange or an o-ring that doesn't have to spin can be sealed with Lock-tite's "Gasket Maker". Just a thin film (.010") on the threads, flange (or gasket) or o-ring and put it togerther normally.
In my experience putting silicone RTV on an o-ring makes it leak worse. If that happens to you try the Gasket Maker.
I have even sealed transmission leakes when the leak is a bolt through to the sump. I just put the Gasket Maker on the oily threads, shaft, and head of the bolt and put it back in. Leak stopped!

 

Suggestions - if you have to replace the pump gasket, get a piece of 4" plastic pipe and a toilet flange. Screw the flange to a piece of 2 x 12 and glue a chunk of 4" pipe to it about 3' long. Stand the trans on it's tail in the tube and it will let you install the gasket and pump DRY, which helps the seal tremendously.
2) place a bead of RTV around the lip of the filler tube above the o-ring. Let it start to set, then install the tube. Let it set up for 24 hours before you add fluid. Do not do this before the trans is installed - do it after it's in the car. If you mess with the tube during install, you'll break the seal.

I run a cast pan and ALWAYS have problems with the dip stick o-ring leaking of I have to disturb the tube after installation. It always looks like it's coming from the pan, but it comes from the tube and runs around the front top of the pan/case area.

 

Have seen the intermediate band adjusting nut drip sometimes. Looks like the pan leak too.