On Dec 2, 4:13*pm, "S. Murry" wrote:
John,

Thanks. *Actually, I think the previous owner may have already used the
"vaseline trick", maybe too many times. *I appear to have a
semi-fossilized covering of what appears to be a vaseline/dirt mixture. *I
think this is actually what may be gumming up the works. *However,
cleaning it from the outside hasn't proven easy.

Well, if nobody else chimes in, I guess I dig in and hope for the best!
I'll certainly post again with results.

DG does sell a valve rebuild kit, which, as I remember, consists of a
replacement spring, O-ring, and a few other random parts. This did
the job when one of my DG-600 valves started leaking. I didn't do it
myself, so I can't help you there, and you'll likely have to pay the
DG tax to get hold of the kit...

Marc