1st valve: this valve used to never cause me trouble at all. THen, suddenly it would stick at the end of the press. I took it home, washed it, cleaned out the casing with the casing brush, cleaned out the holes with a mouthpiece brush, and wiped it clean. Then, i put a bit of oil and it worked fine. Then next morning, i took it out for a second and found it was sticking again. It worked fine afterthat, but why would a valve to that?2nd: this valve is very troublesome. It's sticky for no reason. i did the same thing as the first, but it stayed stuck3rd. Weird valve. One day, i dropped my trumpet (not like down the stairs or anything, just while sitting) and this valve just messed up. What happened, was that when the valve was screwed in all the way, it would be stuck. however, when i unscrewed halfwayor a little less it worked amazingly well. Can a slightly unscrewed valve affect your playing (aside from the clicking noise). Can a valve get dented, causing this?
I think the reason why your valves are sticking is because they are building up sludge from being oiled too much, and yes, that does happen frequently. Remove the valves carefully, wipe them off thoroughly with a clean cloth, replace them correctly, and lightly oil them. Then try pushing the valves a bit before playing.