I was wheeling my 89 (1st Gen) 4runner after about an hour of wheeling I lost power steering. PS reservoir was full, didn't look to be boiling. It obviously was leaking from the PS cap. I trailered it home, started it up and PS was working again.

It has a new PS pump, new steering box, new lines, I have driven it on the street prior to wheeling it with not problems. What would cause the PS to temporary stop working?

I am using PS fluid not ATF.

 

Sounds like it overheated, I would look into getting or fabbing a larger reservoir and adding a PS cooler on it.

 

It's says "Use Dexron type ATF" on my can. With you wheeling your ride and heating up the PS fluid, go synthetic. Redline D4 ATF is a very good synthetic tranny fluid that I have used in my Ford F350 before. I haven't used it yet in my 4Runner...yet. Expensive but worth it to me. Check out this link:

http://www.bobistheoilguy.com/forums...Number=2206764