I have owned our '94 'burb for one year. It has always had a power steering pump noise, like it's under some load all the time. The hydra-boost and steering work fine. Is there any way that the hydra-boost can be restricting flow, causing the pump to build pressure all the time, yet seem to function okay? I have rebuilt power steering pumps before, and can't think of anything that could cause them to make noise other than load. Any insights are appreciated.