Posted by Art on September 18, 2001 at 22:30:29:
In Reply to: Valve problem / repair posted by George on September 17, 2001 at 23:31:48:
If it's not an extremely valuable instrument, I would not hesitate to try fixing it myself as an untrained amateur. If I own the instrument then nobody can blame me for messing it up. First you need to find out where the friction is occurring: dry off the piston and cylinder, and then go over the piston with a magic marker. pump it a few times and see where the ink rubs off. It may be the scratch or it may be somewhere else. If you decide to remove a little metal just stay away from the ports. (That's where leaking can be critical.) To smooth down an area that has been sanded or scraped, rub it with the smooth shaft of a screwdriver.