help needed with 904

The piston came out very easy and popped in and out easy and was in pretty good condition All Things Considered. I can put the disc in without the seals easily, I can put the disc in with the outer seal which is bigger than the one that came off of it in relatively easily by itself without the inner seal, but I cannot get it on over that inner seal without the outer seal on and the fact that that seal in particular is not even reversed on its way down on. That push down on it damn near with all my strength twisting and turning with a half a jar of Vaseline.

they should take the same lip seal....the rear drum is always a pain in the *** to get the piston back in...