Taking out the three bolts on my Sherwood Water Pump was hell. In doing so, I stripped out the threads of the impeller cover..OH GREAT....my brother-in-law rigged a simpler, better solution, we replaced the threaded screws with threaded 1/4 "allen head screws, with washers on both sides and the regular nut. BUT, we screwed it in front to rear. Works like a champ, and next time I do this nasty job, it will be easier....The allen screw heads are small, so you don't have to worry about the " regular" bolt head not being flush against the outer impeller cover. The allen bolt head with washers are perfect...Hope this gives hope to other M25xbp engine owners with Sherwood pumps..