Got a ski that had ZERO parts inside the end cap. This is the pump that calls for the following parts 271001124(pusher assembly), 371001107 (slider), 271001108 (spring). I don't see them available anywhere and am wondering if the old simple plunger type pusher and spring would suffice. Ski is a 20002 GTI LE. Help is appreciated. I had the parts but want to replace them. On a side note, I don't like that slider pusher and spring set up on the 155mm pumps.