Rear seal blew out on my 03 700 Sportsman. Removed and tore down caliper, cleaned and checked piston and sleeve and all checked good. Put on new seals, lubricated with brake fluid and attempted to put piston back in. Book says push in while turning but it flat won't go in no matter how hard I push. I even hit it with a rubber hammer and while it went in slightly, it would not go in all the way. If it is this hard to get in my concern is that it will not move smoothly once mounted on the atv. Anyone else have this problem or any hints to what I might be doing wrong?