So I know this is actauly a french horn question, but I'm sure some of you own or have owned a rotary valve trumpet, so maybe you can help. Anyway, I recently picked up my french horn from school the other day, I've never played one before and I know nothing about how these valves work. I was practicing today and I noticed the valve action was kind of sluggy. I unscrewed the top and noticed that they don't even come out to oil them or anything, so I just put a couple drops right on the litle circle thing. It seemed to help. My question is, how do I take care of rotary valves? I know there is the litle string things that I'll have to replace occasionaly but is that all? I didn't mess anything up with a few drops of oil did I? Thanks.