My third valve is always sticking, despite the fact that I oil them thoroughly every other day. It scrapes the sides of the case when I take it out/put it in, it's almost as if the valve is too big for it. Often times it will stick and I'll have to unscrew it and physically pull it out for it to be functional again.I've inspected it, and the inside looks just like the others which are fine. I've tried washing it, oiling it, and putting a trace amount of vaseline on it. What is the problem?
Have you tried cleaning the valve casing (what the valve moves in)? If not, you can use a clean cloth that won't leave fibers in there, or a valve casing brush (couple dollars at the music store) to clean the inside. Many times dirt builds up at the bottom of the valve casing where it's supposed to and the valve eventually gets stuck in it. Also, like the poster above said, the plastic/metal guide could be getting caught. You can use slide grease to lubricate the slot in the top part of the valve (not the casing) where the guide moves. Just don't get any on the piston part of the valve. If all else fails, it is possible that the valve was not honed correctly at the factory and a professional will need to fix it.
Check the spring and plastic valve guide on top of the spring. I've seen these stick and the results are quite annoying, but once the spring moves up and down freely, so will the valve.
