Can a rear main seal leak from just sitting? I've got a leak from my pan and from rear seal area, but I'm just not sure if it's just the pan or also the seal. It's been sitting for a week, and it looks like it is still leaking from that area (out of the bellhousing).

I've got to pull the pan to fix the leak so I figured I'd check to see if it was a galley or cam plug even. Just didn't know if a rear seal could leak without engine running and sitting for awhile.

 

Have you had the seal replaced?

This is a discussion we have had before where people have had motor work done and then a rubber seal is used and not a rope one, the best however were the original asbestos rope ones never leak.

 

yep they will tend to dry up and leak due to sitting,

 

Its a newly rebuilt motor I built. I installed the Fel-Pro Rubber seals. I believe I installed them the way they were supposed to be installed.

Are the Fel-Pro rubber seals just not good?

Maybe it's not even the rear main seal since my pan is leaking also, but it's coming from the area.

 

When I did mine the guy who balanced my motor laughed at the rubber ones, if they are not in right can cause the main bearing hold down piece to cause a gap with the pan, all may be interrelated.

 

Hmmm. So maybe if I have the pan off anyway, I should just go ahead and replace with the rope style seal to save myself headaches down the road? (Thinking that's the problem)

Do alot of people have alot better luck with the rope style seals instead of the rubber seals since that's how they came from factory?

 

From what I hear the ropes are the way to go, there is a thread out there somewhere on here where we discussed, but no idea where at this point in time.

 

Well I dropped the pan today, and the rear seal area looks pretty clean. How can you tell if its the rear seal? Like I mentioned, the pan was leaking also, and I noticed there was a small leak on the rim of the pan by one of the side seals on the rear main, but not sure if it's the pan or the side seal?

 

Is the mating edge of the pan perfectly flat, and what kind of oil pan gasket are you using?

 

The pan looked pretty flush except for the holes that push up from tightening.

Fel-Pro "blue" Performance Oil Pan Gasket.

 

Cork, or paper?

I think I have a fel-pro cork one, am told they make a better seal. I have also gotten into the habit of taking a wooden block and hammer to flush the holes out, generally caused by over-tightening.

 

It's a steel core blue silicone type gasket. I had a cork one, but got tired of having to buy a new ones because I had to take the pan several times off to fix one thing or another when I was doing the swap. So, I just got a reusable one.

I do usually even out the pan flush with a hammer also on the pan, but the pan is leaking on some welds when I had to re-fab the pan to clear the cross member, that's the leaks I fixing on the pan, but just couldn't tell if the spot on the back was a bad seal on the oil pan or, rear side seal leak since it leak after it ran but also after setting for a while.