Rear main oil seal leak

[JimNolan]

Guys,
   I need to find out from your experience if using something like "Barr's Rear Main Oil Leak Sealant" will hurt an engine. I've got a small leak that I'm willing to put up with before I'd hurt my engine but if it'd help I'd use it. I've NEVER used anything in an engine like this before and don't want to damage a very fine running 410 engine. I'm just not physically able to do what I used to before the heart attack. Thanks guys. Jim

[machoneman]

In a word....don't. Those products IMHO are fine for a old leaky engine in a grocery getter. Live with it, I say.

[jayb]

In a word....don't. Those products IMHO are fine for a old leaky engine in a grocery getter. Live with it, I say.

+1 on that!

[JimNolan]

In a word....don't. Those products IMHO are fine for a old leaky engine in a grocery getter. Live with it, I say.

How come I had an idea that would be the answer. Done, If Brad Penn 10W30 doesn't fix it, it won't get fixed.

[My427stang]

It wont hurt anything, but it probably wont do anything anyway.  All they do is attempt to soften old seals, rarely works

[fastback 427]

Tried it on my 76 f350 dually and didn't help a drip.

[cammerfe]

It wont hurt anything, but it probably wont do anything anyway.  All they do is attempt to soften old seals, rarely works

That's the right answer. Modern seals are much less likely to dry out than the older ones. But the old fixes are still sold.

KS

[Chad D]

Maybe fiddle with the PCV choice to pull a bit more crankcase vacuum?

[JimNolan]

Maybe fiddle with the PCV choice to pull a bit more crankcase vacuum?

Hadn't thought of that. I'll check that. I pull 14 inches of vacuum at idle. May need a different PCV valve.

[JimNolan]

Maybe fiddle with the PCV choice to pull a bit more crankcase vacuum?

  I installed  a new PCV valve today. It came in a kit that was marketed by C.R.A.P. I ordered the kit so I could install a PCV valve on my 63 with the 406 and aluminum intake. They advertise the PCV valve as that of the original specs of a 427 Ford engine. It's a nice kit and I bought another PCV valve just like the one that came in the kit, it only cost me three bucks. I took the old PCV valve out of the 57 with the 410 that was leaking and it barely rattled. The new one rattles big time. The new valve is a Fram FV184 and I can't find the specs on it but it's made for a chevy V8 up to 454. I need to find a place on the web that gives the specs for these PCV valves. I hope this helps with the oil leak because it went all summer without leaking and just started this last 1000 miles or so.
12/04/2013 
   I found out by searching the internet that the FV184 PCV valve has a spring in it that takes 117 grams of pressure to compress the internal spring .300", while the FV191 PCV valve has a spring that takes 95 grams of pressure to compress its' spring .300".

Both my cars (406 and 410) have cams in them that give me 13-15 inches manifold pressure at idle. I compared both PCV valves while monitoring a vacuum gauge. Both PCV valves gave me @14" MP at idle and 20' MP at @1500-2000 rpm. The only difference was the PCV valve with the light spring (FV191) was completely closed at idle and the PCV valve with the heavier spring (FV184) rattled constantly, indicating it was closing/opening at a very fast rate. I used the FV184 in both engines.