I've been having trouble with the power steering in the 86 4x4. In the past year I have had 3 ps pumps on my truck, all showing similar signs of problems. There are hard spots in the steering, the pump is loud, and there is significant vibration coming through the steering wheel. The first pump was the truck's original, so I replaced it with a used one off ebay to see if anything changed. Worked great for a few months, then the troubles came back. Then I scored a new "rebuilt" pump off ebay for a great deal...installed that guy and the same old story, right out of the box. Could it be that there is a problem with the steering gearbox? I've already checked the steering linkages and nothing is binding or limiting movement.

Has anyone had good luck with Lucas p/s oil? Im thinking about trying that before I look into anything else.

Any help appreciated...

Scott

It's hard to troubleshoot your problem. Your first pump was stock which wore out. Your second pump was used which was worn causing it to fail so soon. Your third pump was rebuilt, possibly rebuilt incorrectly or who rebuilt it did not know what they were doing.

There's nothing in the power steering gear box which could wear out a pump. I would order a new Nissan pump and be done with it.

I had a similar issue with my 85 720. I never replaced anything even after 165k miles.

What I did was flush the fluid out. Disconnect the hoses at the box and drain as much out as possible. Then bleed per the book. lift the front wheels off the ground and turn lock to lock slowly to self bleed.

Repeat until the red fluid is as clear as new.

I had to do this to my 93 truck (175k) I just bought 2 years ago.