[fredjacksonsan]

After reading the discussion, and I don't mean to be insulting but is the fluid reservoir full to the line? Foaming and noise are symptoms of low fluid.

Also, it might not be the pump, but rather the power steering unit that the pump feeds. Have you checked the fluid in the pumps you've removed from the vehicle, to see if there are any metal flakes?

When you said that there was a puddle of fluid on the ground, what let go and started to leak?