Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

  Sorry to hear the pump is a bit of a problem.
Could you try some waterproof grease of some
sort to coat the inside of the piston and help
it pump more efficiently?  Perhaps the piston
has some sort of flexible washer that needs
replacement.  I've never had my pump apart,
so I don't know how the piston seals.  I'd
say it is a good bet that is the problem.

Good Luck,
Wayne