I'm 99% sure it is not pressurizing but wonder if you used a sealant tween
the seal and case?
"Tri-Pacer" wrote in message
...
Some months back I put a new seal on a C-85 and had it continue to leak.
After a LOT of head scratching it turned out that the breather, which
exited through the cowl, had been repositioned and was pressurizing the
crankcase.

Cheers:

Paul
N1431A
KPLU