Cleaning Valve Slide
If valve slides are stuck, don't use strong-arm methods to get them loose. The result of force is usually a broken brace or a kink in the valve casing. The best method of starting a valve slide not too badly corroded is to put a piece of cloth (a handkerchief will do) through the slide and give it a quick jerk. If this won't do it, try some penetrating oil on the slide and let it stand overnight. A slide which resists all such efforts should be taken to an experienced repairman.
Once the slides are removed, clean off all corrosion with soft clean rag or the metal polish you use for cleaning the outside of your instrument. Do not buff the slides or you will soon wear the slides down until the fit will be too loose and the slides will drop or blow out. Wash the inside with castile soap and warm water. Fill the slide half full of soapy water and shake well. A weighted string and a piece of cheesecloth about 3 to 4 inches wide and 3 to 4 feet long will enable you to remove dirt from the slide crook which you might not otherwise reach. See Fig 18 for illustration of this cleaning device adapted to trombone slides. When the slides are thoroughly washed, rinse them in cold water.
Slide Grease, mutton tallow, vaseline, or cork grease should be put on the valve slides before putting them back in the instrument. This will prevent corrosion, make them work freely, and retard wear. After applying the lubricant sparingly, lap each side in individually by pushing the slide in and out and at the same time giving it a rotating movement. This distributes the lubricant evenly and thoroughly over the slide surface. Finally, push both sides of the slides all the way in and wipe off excess at the joint. This prevents the excess lubricant from getting into the valve slides and then into the valves, where it will literally "gum up the works."
Never try to remove or replace a slide unless the corresponding valve is open, that is, unless the corresponding piston is pushed down.
Examine the water keys. A thin coating of oil will help prevent rusting of the spring. If the cork is defective, supply a new one.