What happens if you put brake fluid in power steering fluid?

Not being a chemist, I'm not sure how the seals will react. I've heard stories about seal swelling problems when adding a wrong fluids to a system. I had tried an experiment, setting seals into different fluids to monitor swelling over a period of a week with no conclusive results. Since the fluids are different, you don't know how the properties aside from swelling will affect the power steering. Such as how well it compresses, viscosity and so on. I would flush the system this week if it was mine. pukenstein@aol.com