I have an LX3310 and had my tractor to the dealer for a repair. When I got the tractor back the bottom on the third function valve was dripping when the tractor was running. I noticed two hex set screws visible on the bottom (6mm hex) and I tried tightening them a little and that stopped the leak. However, what are the set screws used for? If they are for bleeding I think I am fine. If not any idea how they are supposed to be set? Thanks