Either or it's the same concept just changes where the pressure is going to get dumped to. If you don't pinch off that hose, you're sending your pressure outside. You need to seal the entire system in order to hold a pressure and find any leaks. Whether it's a tube that runs to an overflow tank or a tube coming out from an expansion tank, the tube needs to be blocked.
May 7, 2015 at 3:45 AM