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

My brand new Stuart 1/2” diameter ram, hand pump seized. It just got harder and harder to pump. Has anyone had experience with these pumps? I use distilled water, so dirt is not the reason.

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Hi Brad, If the pump is the one in your picture it does not look like a Stuart pump.

It looks like a well finished home shop built piece made from soldered tubing. 
Evidently Stuart has started making these and sell as a package with a make-up water tank.

The original style Stuart Hand Pumps are made from very high quality castings, have a 3/8" diameter piston, and don't have these problems.

If I had bought that from Stuart, I would return it and have them replace it with an original style cast body hand pump. I don't know of any that have failed including those over 60 years old.

This is the pump you need.  (all built, of course)

https://www.stuartmodels.com/product/manual-feed-pump-unmachined/

Best of luck,

Gil