How funny! I had the exact same problem last year, except that the bracket had already been welded (sort of half-assed) and had broken again. Anyway, I just bought a new bracket from the local dealership, it costs about $3 and is really easy to replace. I would suggest doing that rather than trying to plug the lines, it seems to me that would be more effort than its worth, even if you don't use the A/C.