Hey guys, I've had a problem with my Bach Strad for about a year and a half now. My third valve sticks almost all the time. No matter how much oil goes on the things, it sticks. Its one of those things that when you want to show someone it never happens. But it happens atleast once a min. during playing. Most of the time it won't go down without more force than the other two valves. I've noticed it worsens after playing a few lines and also when I have to push the third valve slide out. Any tips?