Hi everyone! I have an old Briggs/Case 6011 toilet that is awesome! Super quiet and love it! Here's the problem... I can hear it "running", however, it sounds more like a quiet hiss coming from the fill valve area. I can lift up on the float rod and that does not help. It is not the fill level as the water line is still under the overflow tube. It is not the flapper either. The only thing that somewhat helps to quiet it, is pressing down with my finger/thumb fairly hard on the water level adjusting screw on the top of the fill valve OR turning the water completely off at the wall (which is what I've been doing) until I need to use it... My question is, what do I need to replace? Should I get the #5101 conversion kit that just has the top parts of the fill valve, or should I get the entire fill valve/ballcock/etc... OR, is it NONE of the above and there's an easier fix?!? I would much rather fix it than buy a new toilet. Thanks in advance for your opinions and advice.