my 81 F150 is extremely hard to unless your going 40mph or more. My powersteering pump is full of fluid. I'm wondering if the pump maybe bad or if it's something else, like the steering box?

 

check for a kink in the powersteering lines. I had my pump off and when I put it back on the truck was hard to steer. Apparently when I took it off I ended up kinking the metal line that runs to the rubber one.



Jim

 

The pump is probably shot. Theyre reliable within limits. Still have my original pump after 170,000 miles.

 

I have seen where the king pins were partially siezed in the IBeams on one side only and it was very hard to steer or turn at low speed Jack up the truck and see if it is tough to turn with no weight on the front end. If your truck has been pulled out of a ditch or whatever someone may have hooked part of the steering parts.

 

Also check for binding on the steering column, ie: sagging cab mounts etc, that could also be an issue.