I have a 2009 focus with 406,800 miles on it and things have just started to need replacing. This time around the power steering pump was leaking and the shaft that the pulley attaches to snapped inside the pump. I replaced the pump the belt, and cleaned all the pulleys because the the grooves were filled with oil sludge. I drove it all over for about an hour and no problems. My wife gets in and drives it two blocks and the belt comes off. I looked at all the pull eyes again and found that the tensionioner pulley was really chewed up so I replaced it. Drove around again and no problems...wife jumps in to go to the store and when she starts it the belt snapped off again. I haven’t replaced the tensioner yet but was thinking that may.be next. All the components pulleys roll smoothly with no binding from what I can tell. Just looking for a little knowledge to help out, thank you.