1988 mj 4.0 auto. About 5-6 months ago and maybe 2000 miles ago I replaced the power steering pump, lines, pully, resivor, and gear box. Replaced the gear box with a 99 Durango box. I noticed the steering would get stuff to the point to where it would feel like it was not working after prolonged periods driving on the highway. I would say 3 miles or more. When I would exit I would notice very stiff or no power steering and then after I would give it some gas it would come back.


However I could be idling in park or cruising around town and never have a problem with it.

So I replaced the power steering pump. This is the third one in 2 months. Same story with all the pumps. Also put another gear box in. Every thing is the same nothing is changed.


Can some one explain this for me? I'm at a complete loss.

 

Possibly pumping up to much pressure on the highway and binding the box up?

 

Possibly pumping up to much pressure on the highway and binding the box up? I would look up specs on steering box and see what the operating pressure is then see how much ur pump is putting out

 

Try bleeding the system. I had the same problem. After driving on the highway the fluid would be full of air bubbles causing the pump to cavitate. Let it sit overnight and then bleed with the front wheels off the ground.