Our previous 1995 Class A on a Ford F53 chassis had zero brake line problems, despite extended runs in upstate NY, PA, etc, in the winter. Our current 2001 Class A on an F53 chassis that runs the same roads did get a pinhole leak in the front brake line where a wire harness covering had rubbed the coating off. That resulted in losing the front brakes, but I was able to make a temporary roadside repair and continue our trip. About $30 at NAPA for a new line and coupling did the job right, and the rest of the lines look ok.