Posted by Chuck on September 24, 2000 at 12:01:39:
In Reply to: My back cap wont budge posted by Chris Morgan on September 24, 2000 at 08:41:54:
Try one of those little sheets of rubber meant to be used for jar and bottle-lid removal. They're often given away free as advertisements. Sometimes, this will get you the traction you need. A little oil where the cap meets the valve casing and some gentle heating with a hair dryer can loosen things up a bit, too. I've also heard of people running warm water through their valves, but never tried it myself.
I use a little (a blob a little smaller than a matchstick head) Permatex anti-seize compound on valve cap threads and have never had a stuck one since. You can get the stuff at any auto-parts store.
Of course, you could also try the escapade I've seen on at least one tuba--trying to remove the TOP valve cap by using a hammer and cold chisel--not pretty at all.