Fixing Faulty Waterpumps

[BejoDesteamon]

Hello All,
I want to bring my O.S. Krauss 3.5" gauge steam loco back to working order, after a 10-ish year hiatus.
However when I tested to see if the axle pump & hand pump feed water, both failed to do so. After removing the intakes to both check valves on the boiler and trying again, both copper tube inputs remained dry. So far the check valves don't seem to be the problem. I'm afraid I'll have to take the water tanks and pumps apart to figure out what is going on. I was just meaning to ask if anyone has some tips and tricks for water pump maintenance on live steam locomotives? What troubles can I shoot when taking them apart? What should I be looking out for?
Thanks for any help!
Bejo

[crueby]

If they use o rings for seals, check that they have not degraded or just need some new grease on them to seal properly. Any dried minerals/scale in the check valve openings keeping the balls from seating maybe?

[john mills]

I would undo and check water flows to the pump inlets then check that the valves in the pumps are free and not corroded  coated in stuff that does not let them seal  i have had to replace balls in pumps not used for a long time  they can have a coating or and can be stuck on there seat.

[BejoDesteamon]

Thank you for the tips, I've taken the pumps apart and found that it was pretty much as you predicted. The axle pump inlet ball was stuck firmly to the bottom seat when I removed it! I've cleaned both pumps up now and they seem to be back to working order. In the process I did discover that the check valves to the boiler were also slightly leaky, so that when filling the boiler with water (without pressure) just above the check valves, one of them already started to drip. Would that be the same problem here? The ball not sealing properly?

[crueby]

Probably. Minerals in the water could have left grit on the surface as it dried, grabbing the check valve balls and/or leaving the surface too rough for them to seal. If thats part of the problem, a bit of a soak with vinegar would help, then a good brushing. Nice that its getting better!

[john mills]

i have found the balls or valves may be stainless or bronze but they still if let for a long time they end up with a coating mine were black  they will be stuck to the seat and the simplest is to replace balls and clean the seat may need re cutting