I am working on this escort that originally had power steering fluid and foam coming out of the reservoir. The owner has constantly added PS fluid in the system, while it actually needed ATF Mercon.

My question is if the PS pump can create the foam problem, or is it more likely to be a pressure line?

I cleaned the area up around the pump, and we are putting it back together to see what the system will do after we add new fluid in.

ANy feedback on what to check, where, etc is appreciated.