727 leaks if not driven

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jdsduster

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if i drive it at least once a month all is well,let it sit longer and quite amount of fluid on the floor.1/2 quart.ideas? dont see how it could be the pan gasket,dipstick o ring or shift lever seal.throw some ideas at me
 
rear seal/front seal or a trans line or the speedo drive gear cover.... there arent many places left
 
jdsduster said:
yea i hear ya,but only after it sits for longer than a month?thats whats got me
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i dont know why i even asked, i already know i got to get it on stands,wipe everything down,and go from there.sorry
 
jdsduster said:
if i drive it at least once a month all is well,let it sit longer and quite amount of fluid on the floor.1/2 quart.ideas? dont see how it could be the pan gasket,dipstick o ring or shift lever seal.throw some ideas at me
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I had the same problem, Mine was leaking from where the speedometer cable went into the transmission. Easy to fix, just two small rubber seals. MMG
 
ive got the same problem with my 79 power wagon been sitting awhile left a big mess in my drive changed front seal when i pulled the motor havent got the new motor in yet but no leaks as of yet
 
i had this question in transmissions class hehe........the amount of ATF in the case AND torque converter is more than the case itself can hold........from the minute you shut off the engine fluid is leaking back from the torque converter back into the main case .....under normal usage this is a very smalll amount thats unnoticed bcoz the second you start the engine it goes rushing back into the the torque converter ........if its parked for extended time the fluid that leaks back into the main case, over fills the main case and leaks out through the vent..........thats why cars parked for years always have puddles underneath them .....then when you start it ...all the fluid goes rushing into the torque converter depriveing the main case ....making it not engage and ppl usually say "oh no the trans is bad" when most of the time if you top it off with fluid it will run fine even after many years........im betting if you track where its coming from .....its coming from the vent........and a possible solution to this is if your going to store it for extended time get a pan that has a drain plug and drain the main case when it goes into storage ....just dont forget to refill it.
 
RaniDart70 said:
i had this question in transmissions class hehe........the amount of ATF in the case AND torque converter is more than the case itself can hold........from the minute you shut off the engine fluid is leaking back from the torque converter back into the main case .....under normal usage this is a very smalll amount thats unnoticed bcoz the second you start the engine it goes rushing back into the the torque converter ........if its parked for extended time the fluid that leaks back into the main case, over fills the main case and leaks out through the vent..........thats why cars parked for years always have puddles underneath them .....then when you start it ...all the fluid goes rushing into the torque converter depriveing the main case ....making it not engage and ppl usually say "oh no the trans is bad" when most of the time if you top it off with fluid it will run fine even after many years........im betting if you track where its coming from .....its coming from the vent........and a possible solution to this is if your going to store it for extended time get a pan that has a drain plug and drain the main case when it goes into storage ....just dont forget to refill it.
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yea thats kinda the case,shifts fine after i refill it,no issues.my other mopars dont have this issue,its the 61 that cries after sitting.i was kinda thinking the vent.i will know for sure once i do what i said.thanks for the input guys.
 
Ya, My Dart it was the shifter shaft seal. Like said above the converter drains back and floods the seal after it sits a few weeks. As long as I drove it, not a drop.
 
RaniDart70 said:
i had this question in transmissions class hehe........the amount of ATF in the case AND torque converter is more than the case itself can hold........from the minute you shut off the engine fluid is leaking back from the torque converter back into the main case .....under normal usage this is a very smalll amount thats unnoticed bcoz the second you start the engine it goes rushing back into the the torque converter ........if its parked for extended time the fluid that leaks back into the main case, over fills the main case and leaks out through the vent..........thats why cars parked for years always have puddles underneath them .....then when you start it ...all the fluid goes rushing into the torque converter depriveing the main case ....making it not engage and ppl usually say "oh no the trans is bad" when most of the time if you top it off with fluid it will run fine even after many years........im betting if you track where its coming from .....its coming from the vent........and a possible solution to this is if your going to store it for extended time get a pan that has a drain plug and drain the main case when it goes into storage ....just dont forget to refill it.
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I must be lucky some of my cars sit for a month some 4 months over winter , have never had this problem . Will know what to do if I see a puddle of ATF under the car from now on though .
 
My 66 coronet 318 Poly with the 727 did the same thing. I checked the seals & gaskets & all were good. Then I decided for some reason to grab ahold of the driveshafl slip yoke & it moved up and down. I had removed the tailshaft housing & replaced the bushing. No more movement from the slip yoke & no more leak.
 
They just do it, from the front, usually. Never have figured out whether front seal, or pump housing. Run it reg, and no leaks.
 
The converter drain back is quite common when sitting for any length of time...
One if the most over looked leaks on a 727 is the rear band pin Oring.
This Oring is at the rear of the transmission ABOVE the trans pan rail consequently is seeps down to the pan gasket area and it usually gets diagnosed as a pan gasket leak.
Its not a simple fix ... it can be complicated if your unfamiliar with automatics. It requires extension housing,pan and usually valvebody just to push the pin out enough to replace the Oring. Probably best left to your local transmission shop.
 
So can anything be done to prevent this , lets say if the car will be sitting for 3-4 months ? Would draining fluid from the cooler lines help ? I've never had this happen , but would like to prevent if possible . Any suggestions ?

Another question , is this just a 727 problem , or all automatic transmissions ?
Thanks
 
jerry6 said:
So can anything be done to prevent this , lets say if the car will be sitting for 3-4 months ? Would draining fluid from the cooler lines help ? I've never had this happen , but would like to prevent if possible . Any suggestions ?

Another question , is this just a 727 problem , or all automatic transmissions ?
Thanks
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Really no need as long as all the seals in your trans are in good shape.
It usually occurs with older/high milage transmissions as the seals-gaskets and Orings become hard,dried out and shrunk. How to prevent it....... Have the leaking areas PROPERLY repaired and you should be able to store your ride without leaks. Don't be fooled into hearing thats just the way they are, they all leak. Usually either a seal surface is worn or the tech misdiagnosed it. If you have multiple leaks you might consider removing the transmission for a COMPLETE reseal. Oh... and stay far away from offshore seals !!
 
My brothers 72 Chevy El Camino does it so I don't think it's only torqueflites
 
68-GTS said:
Really no need as long as all the seals in your trans are in good shape.
It usually occurs with older/high milage transmissions as the seals-gaskets and Orings become hard,dried out and shrunk. How to prevent it....... Have the leaking areas PROPERLY repaired and you should be able to store your ride without leaks. Don't be fooled into hearing thats just the way they are, they all leak. Usually either a seal surface is worn or the tech misdiagnosed it. If you have multiple leaks you might consider removing the transmission for a COMPLETE reseal. Oh... and stay far away from offshore seals !!
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Okay , that makes sense . I 40 years of mopar products have never had that problem , ols seals , yeah that will do it .
Thanks
 
too funny we all have this problem

ITS THE SEAL IN THE DIPSTICK PUT SOME BLUE SILICONE AROUND IT THE SEAL cant hold the little bit of tranny fluid draining back out of the tourqeverter it sits up in the dip stick and leaks out ever so slowlley its a ***** to find pull the stick bolt pull the stick housing up and smear silicone around it after u cleaned it off good then put back together let sit 24 hours drip fixed now you can clean up any silicone you dont want to see all mopars get the drip lol
 
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