4L80e front leak issue help…looking for a good shop

[yellow1098Greg]

Hey guys I was wondering if anyone knew of a good transmission guy in central Florida that could help me with this. Most shops only know stock step ups unfortunately.




I have a freshly built stage 3 4L80e that I recently bought and am having a leak once pressure builds up from the two lower bolts of the front adapter plate of the Ck performance adapter it has on it. Maybe it’s the pump seal but I’m not sure. Thanks so much! The leak can be seen in this clip


https://youtu.be/xhYU5XrtL-4

[Vimes]

Freshly built means it should go back to the builder. But, near as I can tell from the video it also looks like the fluid is coming out of the dipstick hole and working its way around to the front of the bellhousing.

Two things come to mind - First, the dipstick seal should fit tightly in the trans, and the dipstick should fit tightly into the seal, with the seal being installed on the dipstick tube first then pressed into the trans. A little Vaseline on both sides of the seal should help them slide together, and is compatible with trans fluid. If the seal does not fit tightly against both, and is not bolted into place, fluid can leak.
Second, there is a vent tube on top of the trans. If it's plugged or pinched, the trans will not be able to vent excess pressure and will push fluid out. The rubber seal around the dipstick is the weakest seal on the trans since it's press-in and thickish rubber, everything else is bolted together with close together bolts and a much thinner gasket pressed between stamped metal, or metal on metal.

You can use a clean paper towel, now that it's been run, to see if the fluid is coming out of any of the pump bolts. Run it around the inside of the bottom of the bell housing between the trans and the torque converter, if it comes back clean there's no leak from the front. But I didn't see anything coming out of the front in that video, just the dipstick tube. From the leak location, a dipstick tube leak can leak between the trans and bellhousing.

Sorry, can't recommend a shop in Florida, haven't been there in 30 years.

[yellow1098Greg]

Thanks so much for the reply and info…..I will absolutely double check the dipstick tube seal as well as the vent…if in fact the dipstick tube is where it’s coming out of it should be wet around the base correct? Thanks a million again

[Vimes]

Judging from the red I saw in the video, it's wet all over there now. But yes, that whole area should be wet.

[Steve68]

Front pump seal would be coming straight down from behind the convertor, dipstick there always a pain,

Are you looking for a trans shop or someone to fix the dipstick and leak???

[yellow1098Greg]

So it turned out! When the stock bell housing was cut off for the adapter plate it wasn’t a clean cut and had a lip on it that caused the leak. I pulled it and used a grinder on it and got it to seal tight and boom no more leak. Thank you guys for your replies and suggestions