My '95 FZJ80 had a noisy, low-boost PS pump at about 100K miles, so I bought a reman from Toyota. A few years later and 40K miles, it too was noisy and lacked boost. Lately, it had gotten a lot worse. Rather than toss another $300 pump at it, I added a partial bottle 'Rislone power steering conditioner' to the system. I added some, let it run, siphoned out the reservoir, etc. until I had added about 6 oz from the 12 oz bottle. The stuff looks 140 wt. gear oil on a cold day - about like honey. It has, however, completely quieted the system and the boost is back. It may dissolve all the lines and seals - we'll see about that.
is happy now, and that matters some.