I haven't done a gas pump, but lots of hand water pumps. I've honed the brass cylinders with the finest grit stones, this and a new leather makes them work like new, pumping out water on the 1st stroke. I use a Ammco flat stones, not the ball stone type. It's funny to see "city folk" come and pump water, like cartoon characters they "pump like crazy" water comes out the top sprays them. Just thinking out loud anyone used one for a water pump? or to water the yard? Take care! tt