I've hunted all over town at the auto parts stores for AT-205 Reseal and have been unsuccessful, it was sold out everywhere, or unavailable. I found Bar's Leaks Rear Main Seal Repair at an AutoZone, and based on Scotty's liking of their head gasket sealers, I took a chance and tried it in my 1979 Pontiac Catalina last week. I wanted to see if it might stop an oil leak that popped up shortly after getting it driving again. I haven't smelled anymore oil burning, nor have I noticed anything dripping underneath the car after parking it, I've driven about 60 miles on the highway and about 50 miles in town. Has has anybody else given the stuff a try? Seems to me like it's pretty good stuff.
Good to know, it probably works in a similar manner on rubber seals. (I wouldn't expect either product to work on the older type rope oil seals but I think the last engines to use those were sold in the mid-1960s.)
I've heard mixed reviews on it.
Honestly I think it depends on how bad of a leak you're trying to fix with it.
I noticed the container is significantly larger than AT-205, so it must not be a concentrated polymer. The oil was all around the rear end of the motor and in the bell housing, and it only seemed to start after I took it on the highway once. I figured probably a rear main seal. Higher RPMs on the highway probably made it start leaking.
If the stuff worked the seal must have just been hardened and a bit shrunken. If actually cracked/broken nothing put in the oil would have helped.