I've never used 15 psi. But I can tell you that a rear main that's good won't leak at 5 psi.
Doug
I could feel air coming out at 5 lbs just faintly. Was trying to get the soap up in there and it was difficult. Boosted the pressure and it clearly blew air from the passenger side of the crank flange. Definitely eliminates the cam seal and threaded plugs from possible issues, so I think I’ll button the trans back up, replace the VC gaskets and run it once more just to be sure they aren’t the easy fix.
