HELP !!! 727 with a trans leak

[sixty8fivehundred]

Hey guys i work for Chrysler dealer, I've recently had a few mopars come in.
I had a 69 SuperBee come in with a few transmission leaks, I ordered a reseal kit from Mancini. Its main leak was from the front trans oil pump, I replaced all the exterior seals replaced the o ring around the pump as well as the converter input seal. Long story short, test drove and let sit overnight. I came in the morning to a puddle, coming from the front pump. When i opened the reseal kit i wasn't convinced with the paper gasket, but i had no other choice. Are there any better kits or front pump seals? any recommendations?
I followed the reseal procedure by the book and torque specs from a few shop manuals I have for my 68 Coronet.

 

[Hemi Rebel]

Thats a tough one. Unless there is some imperfection in the sealing surfaces i cant see why it would be leaking with new stuff.. i have never seen anything other than a paper gasket to go between the pump and the case, with the rubber square cut seal around the outside of the pump. I have even had them tight and then realized i forgot something and had to go back in without hurting the seal or gasket. Usually a common place for a leak it the dipstick tube seal. Make sure its not running down from there and dripping from the bottom of the belhousing. Sounds like it may have to come out again. Maybe the square cut seal rolled when you slid the pump in the case.

 

[Greg Ducato]

Could it be the front pump bolt washers or even the plug for the band lever pivot stud?

 

[racedodge]

The paper gasket that mounts in between the pump and the housing is legit, I would not worry about it.. I have overhauled/rebuilt over 45 727's and have never had a front pump leak that came from the pump to housing gasket or the o-ring. Now with that being said if you have removed the front pump, you should have put on new bolt washers at the same time (front pump bolts). there has been instances where a leak would form if you used old ones (not with me, but another reputable builder had that happen a time or two).

after changing front pump seals, you should always take some emery (sp?) cloth and debur the torque converter hub (the part that slides onto the input shaft and wear the seal meets). now if you have found that the front pump seal is fine, then it may be a hairline crack in the converter itself that causes a leak only after the transmission has warmed up (heat expands) hence fluid finds its way out, especially with the assistance of centrifugal force.

I would check the welds around the hub of the converter and pressure test your converter if your front pump seal is in good shape.

edit... did you lube up the o-ring prior to installation of the pump to the housing? did you lube up the front pump seal prior to installation of the torque converter?

 

[Ron 73]

Have to say there's a few real nice Mopars in your post!

 

[1948 santa]

Make sure selector shaft seal is not leaking also throttle shaft seal will only leak when sitting for longer times.

 

[okiemopar]

I've got 2 that I haven't got to stop leaking yet. One of them I've had to two different shops and a new pan and all and it still leaks. Every seal and gasket on it is new. Ronnie

 

[71 Meep Meep]

I've got 2 that I haven't got to stop leaking yet. One of them I've had to two different shops and a new pan and all and it still leaks. Every seal and gasket on it is new. Ronnie

Then someone has done something wrong or missed something.
That transmission never leaked when it was new and if "every" seal-oring was replaced then one of the surfaces that the seals ride on has to be worn... You may not see it but a good tech will measure the tolerances and check everything. Don't fall for that "they all leak " because they don't.
It is not uncommon to get faulty seals and for converters to crack....Don't use offshore.

 

[sixty8fivehundred]

I appreciate your guys' input, i will tear down and rebuild this week, the leak is coming from the front pump area. i resealed everything else, thread sealant. I'll post more pictures soon. Its taken me forever to get on here since i work two jobs, one pays the bills the other funds the mopars.

 

[sixty8fivehundred]

The paper gasket that mounts in between the pump and the housing is legit, I would not worry about it.. I have overhauled/rebuilt over 45 727's and have never had a front pump leak that came from the pump to housing gasket or the o-ring. Now with that being said if you have removed the front pump, you should have put on new bolt washers at the same time (front pump bolts). there has been instances where a leak would form if you used old ones (not with me, but another reputable builder had that happen a time or two).

after changing front pump seals, you should always take some emery (sp?) cloth and debur the torque converter hub (the part that slides onto the input shaft and wear the seal meets). now if you have found that the front pump seal is fine, then it may be a hairline crack in the converter itself that causes a leak only after the transmission has warmed up (heat expands) hence fluid finds its way out, especially with the assistance of centrifugal force.

I would check the welds around the hub of the converter and pressure test your converter if your front pump seal is in good shape.

edit... did you lube up the o-ring prior to installation of the pump to the housing? did you lube up the front pump seal prior to installation of the torque converter?

Unfortunately due to the owner wanting his baby back, I was rushed through the process of inspection. I did however clean and lubricate everything with Automatic Trans assembly lube before putting it back together, wish me luck.

 

[racedodge]

good luck!

 

[RustyRatRod]

Have you thought of having the converter magnafluxed around the snout? We've had it done a few times and it helps.