The problem "could be" from the installer not flushing the power steering fluid before the installation. After the car runs for a minute or so, put your finger in the fluid and pull it out. Look at your finger and see if you see any metal flakes. Its a long shot, but you never know. Fred Jones used to make a power steering fluid filter years ago. If you could find one from anybody, that should take care of the fluid problem....even if the installer doesn't flush the system.
If the installer flushed the fluid ( I doubt it), the only other thing I could think of is the racks themselves. I know for a fact that Ford only rebuilds theirs. You can't even buy a new Ford rack. All of them are rebuilt in Mexico. If it is any other rebuilt brand, you can bet money its the rack. Get another brand.
