Transmission front pump seal

I was just thinking it is the seal on the input shaft but you say more likely its the seal behind the pump? All I can tell is the fluid is coming out of the inspection cover. Im trying to figure out how high I will need to have the car?

You'll need the car as high as you can get it on jack stands. When you remove the inspection plate, make sure you mark the flexplate to the convertor so the bolts line back up properly.

I've replaced just the front pump seal before and it cured my leaking problems. Make sure you lube the seal with ATF before sliding the convertor back over it

Good luck

Yes, get the car as high as you SAFELY can on jackstands.

Long ago, I used to do trans work for a living. We would never pull a trans and and just do the convertor seal. We did not want to take the chance it was a pump gasket or O ring.

In your case, it might be Ok to just slam a seal in. Look at everything in there real close before you reinstall.

Well I will order the gasket and o-ring so I have them on hand. I just cant seem to find part numbers for these two for a 727 trans.

I have always changed just the input seal on one that has a leak from inspection cover area.

I use a good seal from a mopar dealer and not the cheapy ones from auto parts stores.

might as well do the front input seal,shift selector seal,TV seal,dip tube o-ring, new style pan gasket,rear seal. while you have it out.

if you drop the VB for the TV seal that would be a good time to replace the tail housing gasket and the low/revs pivot pin o-ring.

I have used a lot of JY trans and changed lots of them over the yrs. I have never had the pump seal or o-ring leak on one that has been in srvice a while. always the input seal or the TC snout causeing the leak.

I suggest 4 tall jack stands and remove as much exhaust pipe as you can.

2'x2' square 1/4" plywood piece is nice to use under the pan and jack pad.

I drop the return line on the rad and run the trans in N to empty the trans fluid out so not to make a mess removeing the dip tube or lines.

be safe and good luck.

See pic for part numbers

If it leaked from the start and it was rebuilt, I would also suspect the vent. Be sure the trans is not overfull.

I really appreciate all the tips and part numbers!!! Thanks guys this leak has just recently started and got worse as I drove it this summer. Trans was built back in the 80's

some people tap and plug the front vent then put one in the tail housing? something similar to the vent on the rearend? i have seen this before in a manual on rebuilding the 727. i do know that if you pull the pump to inspect make sure when you reinstall it the trans is straight up and down or you run the risk of pinching a clutch disc when you put it back together. been there before and pulling the trans again wasn't fun!!

Would the vent leak even after 2 months of sitting???