99 Ford Expedition 5.4l tranny issue

kevinu

i was going down the highway and noticed some smoke coming from the back of my truck. i was a ways away from home so i took it easy on it to try and get home. halfway home the little smoke turn into a complete smoke screen and smoked out a 3 lane highway. i pulled over looked underneath and the was a large solid stream pouring out from the bell housing. i got it towed to my brothers shop he dropped the trans and the pump seal came out. it was not distorted or wrecked in any manor. my brother replaced the seal with a new one and filled trans back up and everything seemed fine at first. well after 10 miles into my trip home it wound up happening again the new seal popped out and all the fluid drained out. we are lost what could be causing the seal to push out so perfectly the seal doesnt get wrecked. its almost like the pump is building to much pressure or something is clogged and its getting backed up even though it drove fine until it the seal popped out. any ideas?

thecardoc3

Wear in the front pump bushing allows fluid under pressure to get the rear of the seal and push it out. It's common to see that the transmission is overheating when this occurs due to low flow through the cooler.

Typically the fix is to replace the convertor and rebuild the front pump, as well as replace the transmission cooler. If you have the radiator cooler that usually gets eliminated and a large external cooller is installed.