Any reason I can't use a shortened Foster style check valve in a pumper? It will ride in a 5/32" (or maybe 0.160") hole in the front of the valve, and only has about the same area around it for headspace as a 0.040" - 0.060" hole of the same length (I was thinking about 1/4" - 5/16" long for the stem).... They don't use springs in a Foster to help it seal and I'm thinking of trying it that way, just a small pin in the valve to prevent it from falling/blowing inside on the fill stroke....

Anybody done this, or forsee a problem doing it?....

Bob