So, after many years of Weihrauch ownership, this will be my first HW that has needed anything doing (other than a couple of cheapies bought as projects or optional fettling).

I bought this new in 2010, so 15 years old. And, just now, on the odd occasion when priming, you can tell it's not building enough pressure. If you back the piston back up and then re-compress, the pressure builds.

Still blindingly accurate, though.

So, I have a new piston seal. It looks amazingly simple to do.....back the retaining grub screw off and push the pin out securing the pump rod and simply pull the piston out? Then swab the cylinder to ensure it's clean, remove piston seal and thoroughly clean the piston. Maybe dress the air intake on the inside a little to ensure no sharp edges?

But what lube? I had been thinking of just wiping a drop of Pellgun Oil on the seal. But would silicone grease be better? And anything to do to the piston body, like buffing some moly paste in or leave alone?

Cheers peeps.