Hello, I have a friend that has the 1st Gen 4x4 S10 Blazer with the 262ci V6 (4.3L) and an automatic behind it - not sure what model of AT. They just replaced the front main seal on the transmission, when the engine is off it does not leak, however when the engine is running the ATF gushes out like a faucet on high. Its coming out of the front of the tranny, collecting in the bellhouseing, then gushing out of the bellhousing. I'm not too keen when it comes to automatics but something is realy a miss here lol. Is the transmission blown? Is there another seal up front that could have been missed? Could the torque converter crack? Something to do with the valvebody deal? Or could it simply be the wrong seal? I am at a loss of what it could be.
Any and all thoughts/ideas/advice would be greatly appreciated.
Thank you.

 

Sounds like you might have a leak in the main pump seals.