Almost no power steering

How old is the fluid? Fluid Level? Type of Fluid?

If the fluid is old (original) I would reccoment sucking out the resvoir - installed new fluid and cycling the rack and repeating until the fluid looks like new. You should NOT end up with foaming or bubles - if you are getting this let the system sit and settle and re-check. You may have a pump going bad or a rack by-passing issues.

Headgasket*

I don't know where i read this but iirc some one said the hoses after a while start to deteriorate from the inside? Could just be a piece of rubber slowing the fluid down. Again i can't remember where i read it but i guess it sounds plausible