Have a '93 302 with a 142k that is leaking through the main seal - not too bad but enough to create a small puddle overnight. I'm figuring a main seal replacement won't be cheap. Curious if anyone has had luck with any of the stop-leak products available and if so, which one. Thanks in advance for your reply.

 

front main or rear? If the front main is leaking, It is a pretty cheap and easy fix. I would never use stop leak except as a last resort. It hasn't worked for me in the past.

 

They supposudly clog everything. If it stops your leak think about what else in your engine it'll be clogging up. Only leads to more problems later.

 

Yeah I was thinking the same thing. Both the front and rear main seals are leaking, but the rear is the worst. I was just looking for a "cheap" fix, but "cheap" usually comes with a price tag all its own. Thanks of the response.

 

Negative.

 

Most stop-leaks have the equivalent of brake fluid in them. They soak into the rubber of the seals, causing them to soften & swell. So they might seal a LITTLE better for a LITTLE while, but then the rubber wears away & you've got a bigger problem than you did before.

Changing a front main seal is easier than it sounds. Remove the belt, pull the harmonic balancer, use a seal removal tool to pop it out, tap the new one in (a huge socket or short PVC pipe section work well), & put the balancer & belt back on.

If you're talking about the rear main, that's a little more work.