m4250t
I just had a perplexing situation. I started a freshly built 401 and after running at 2000rpm for 5-10 minutes( flat tappet cam break-in), the front crank seal pushed out rusulting in a nasty oil leak situation. My first thought was case pressure, but I am running a PCV and the oil filler tube was unrestricted. Anybody have experience or thoughts. Randy
ol' school power
Are you talking about the metal shell and all coming out or just the rubber?
It would take more than case pressure to push the shell.
m4250t
It was shell and all that came out. I am starting to believe it must have been a weak seal or possibly it got started crooked on assembly then weakened as it seated. That's just a guess as I haven't been able to come up with a better theory. I can't believe there was that much case pressure. I will try a new seal and see what happens.
ol' school power
There's no way any case pressure pushed out the shell.
How tight did it fit?
Any chance the crank gear wasn't all the way down when you put the cover on? Or a key sticking up during install ?
If it were crankcase pressure, i'm pretty sure it would have blown the pcv out of the hole and possibly the intake end seals and valve cover gaskets first long before a crank seal.
m4250t
Yeah, I have been having trouble believing the case pressure theory myself.
It has been about six months since I put the engine together so my recall on the instalation is a little vague, but I am absolutely sure the gear and key were seated before the cover went on.
After we discovered the leak, I was able to reach up there with a small bar and push the seal back in. Of course the seal lip leaked then, but I did think that the seal slid back in a little too easy.
Maybe new seal will make the problem dissapear.
On a happy note, the engine sounded great while it was running.
