You always want to put the T up so it will rid the system of air. As the system is running you will start to notice little (soda size) bubbles form in the fill tube just give the tube a light flick with your finger and the bubbles will rise to the top. Eventually the bubbles will go away and you
might notice a slight decreas in temps. As far as draining it goes go to Fred Meyer and pick up a transfer pump, I bought one there for $10.00, works very slick