First thing I would do is to verify the other hose is not leaking. If you think the might, just might be a leak in the HP line then replace it too. The metal line you are talking about is actually the cooling line. Since it is metal, unless it is damaged it's not likely to leak except at the hose connection. Replacing the HP line is a PITA and I would not recommend tackling it unless you have good mechanical aptitude, small hands, and a lot of patients. I only possess one of those qualities and struggled mightily. If I had it to do over I'd just pay someone to do it. It did help though to remove the steering pump pulley to get better access.