I opened the hood and the high pitched noise seems to be coming from the power steering unit. The belt looks fine and has no cracks, but I'm assuming that it's slipping. Or has my power steering unit gone bad? If anyone knows how to fix it, or has any useful information, I would really appreciate you helping out.
P.S. There is no leak in the fluid, but I've only had to top it off once with the Lucas Power Steering Oil.

Thanks.