I thought I read a post that people were putting gear oil in the power steering. I think the problem with my ps is the oil gets super thin when hot. My ps works when it's cold and after I drive a bit it slowl y stops working!
I'm no expert on power steering, but all car fluids break down over time. Might just be that the fluid thats in there needs replacing. (It's auto tranny fluid.) There on posts on draining/filling the PS pump. (It's a cheap and simple thing to do also, so can't really hurt.)