I want to flush my power steering on my 2000 F250 V-10. I have read the directions on flushing it. My question is-It says to attach an extension hose between the ps return hose and and empty container. What size extension hose and plug for the reservoir will I need? Which one is the return hose, the fat or skinny one?

 

I believe the return is skinny, but not positive.

I took the easier way out as my old fluid was in pretty decent condition.
Suck the reservoir dry with turkey baster, refill. Drive truck. Repeat several times. Yes, you use more fluid this way, but system doesn't hold much.
This obviously never gets ALL the old fluid out as it is always mixing some old in the new, but it is far better than not changing at all. After 4 or 5 suck and refills, it should be at least 90% fresh. If the old fluid had been burned or nasty, definitely would have done it right.