My 06 started to feel like it has air in the brake and steering system. The abs light comes and goes as well. About a year ago, it felt similar and I replaced the master cylinder, since it had a small leak into the cab. I also replaced the power steering pump since it was leaking as well. It seemed ok for a while but started acting up again. I know we have bad steering boxes and was wondering if that is causing the problem. It leaks right above the pitman arm as well.