I've tried sealing the connections with teflon tape through the air (ordered separately) and it's leaking. Very bad. Tapped the tank threads with a 1/4 NPT tap and used blue Loctite and finally sealed it. Thought the threads were a little out of round, probably welded on after the threads were cut into the plugs. I figured buying a well known brand like Viair would fix all the problems. Annoying, but if you take your time it will eventually seal.