I decided to rebuilt the water pump on my 1999 YZ400F. I got the right crank case off and disassembled the water pump and I started to take out the oil seal and the bearing and everything came out ok but I had a problem getting the new oil seal in so I started to punch it in and the seal just fell apart. I mean the seal just ripped into two pieces. I know I did not install int correctly.....Does anybody know how to get that seal in... I mean does anybody have a way to punch the seal in without messing up the seal???? Any help would make my life a lot easier Thanks everybody!!!!! Patrick M.