Are you talking about the hose that's for purging the air out of the head? Usually located on top of the head, at the highest point? If so, does it have a bleeder valve on the head, instead of the hose? If it doesn't have either of the two, you need to drill a hole at the highest point of the head, and put either a bleeder valve there, or put a fitting there and run a hose to the top of the radiator. If it goes to the top of the radiator, it has to be at the very top, where their is no coolant. Some people think that you can hook that line in the middle of the radiator, but that could force the air to stay trapped in that hose or in the head.