Recently i have noticed when i turn the tub fixtures off i hear a hissing sound as though my hot water is still running. I play with the knob until the sound subsides but my faucet still drips. I tried loosening the screw and stem on the hot water but i may have tightened it to much too because now the knob is a little more tighter than the cold knob and it is now causing a sound as if air is in the pipe. My question is how do i get the water to stop dripping as well as get the air out of my pipe.