I HAD a severe leak on my pitman arm shaft O-ring for the power steering gear box in a 1995 Mercury Grand Marquis. I added one 12oz. Lucas power steering stop leak and the leak stopped shortly later. This saved me some where between $350.00 to $500.00 to replace the unit for a 50 cent seal. Thanks for your fine product recommended to me by a co-worker. I also use your motor oil and transmission fluid additives.