Specifically early 2000s subarus, if that makes a difference. I've happily never had any cars with power steering issues in the past so I have almost no experience here.
When we first got the car the power steering felt basically broken - sometimes fine, sometimes no assist at all, most often it would come and go as the wheel was being turned. The previous owner "put a pump on it" but as far as we can tell it looks like it's a used parts pile pump, not new or reman. So we figured it needed bleeding, we did that a bunch but couldn't get it to stop generating bubbles. The feel got a lot better but it clearly wasn't fully fixed. Then driving it for a while it seemed to get to the point of nearly if not fully fixed. Then let it sit overnight and came back to it the next morning and it's back to acting up at least a little bit. Is there an obvious culprit or solution here? We don't know the car's history but from the state of the brake rotors it had clearly been sitting for a while, so maybe there's some seals somewhere that need to work back in? None of the parts are incredibly expensive but we really don't want to go throwing parts at it not knowing what the issue is.
