I have a 10 year old AFCO aluminum radiator in my '37 that has begun to seep where a couple tubes enter the bottom. No one wants to repair it or can repair it. Stop leak is what I am being told to try, just didn't want to add that with a new heater core recently installed. Thinking about a pump and hoses to circulate water in radiator only with stop leak, Does stop leak need heat to work? Is one better then the other? Does it need pressure to work? Not really interested in the brass verses aluminum radiator debate!