| There are a couple of possibilities here. One would be dents in the valve casings. Even the smallest dent in the casing will make the valve hang up. Another is gauling. Some of the brass instruments I've seen in the last few years get a nasty yellow-brown tarnish on them when they are played a bit. This is caused by bits of brass from the casing sticking to the valve. It is caused by the alloy that the valves are made from. This can cause the valves to stick. I have also heard that some brands of valve oil are causing a very similar effect. Not having seen your horn, my bet would be dents in the valve casings. Take it to your local instrument repair technician. They can tell you what is up with the valves.
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"Music is a fire in your belly that has to come out of your mouth, so you'd better put a horn in the way before someone gets hurt" (paraphrase of Bleeding Gums Murphy) |