Stirrup pump problem

[clunge]

3 months ago, I bought a secondhand Gunpower pump.
I use it daily with no problems.
But over the last 4 days I have had increasing problem.
On the upstroke, about a third of the time, no air goes into the cylinder, resulting in the handle going down again under vacuum, with no resistance.
On the downstroke, a third of the time, there seems to be double resistance and the pressure goes up by about 4 bar on a single stroke.

This destroys my rhythmn and makes it hard work.

Any suggestions? Apart from get a dive bottle.

[clunge]

I've taken off the sintered filter on the body of the pump and that seems OK.

I've taken off the 'trombone' tubes from the body of the pump and there's not much to see except a slightly shaved O-ring at the base of the nut which holds the tubes to the body. This shouldn't matter unless the shavings have gone into the tubes.

There were a couple of drops of water in the cavity at the base of the body of the pump.

What next please?

[si7777777]

Hi,
I've got the same problem with mine only worse.
I to would be interested and appreciative of any pointers

si

[angrybear]

sticky valves by the sound of it.

[clunge]

That sounds about right.

Specifically the intake valve.

Some guidance on where we could find seal kits or strip down guides would be appreciated.

[JIMBO97]

my pumps gone the same way......seems like a pattern forming here. What is it with Gunpower pumps