Power steering turns into manual hard steering, on occasion...intermittent for about a year. Replaced rack and pump. Noticed that after reaching speeds over 50 MPH, the power steering comes back to normalcy. No problems for a few days, then...hard steering comes back. Maybe air trapped in the system? Suggestions?

 

Was the pump/rack properly bled after the change?

Is it really the rack/pump? How are the joints in the steering column? They can bind up and get VERY difficult to move.

 

The joints were replaced about 2-3 years ago. Now that you mentioned about the bleeding, the pump was installed with fluid, the truck was put up on jacks, and the steering wheel was rotated back-and-forth several times to get the air out of the rack. Is there a more efficient/effective way?

 

Was the engine running while you were turning the wheel?

 

Not at first. Turned the wheel 15-20 times, lock-to-lock. It still felt stiff. Then it was cranked over a couple of times during the process. Do you think that could be the culprit? Air may have gotten back in during the start-up?

 

More likely all the air didn't get purged initially. Jack up the front, let the engine idle, crank the wheels lock to lock a couple times. Check the fluid, If it is still rather foamy, let it sit for 30 minutes or so, then do it again. Keep doing that till you don't see foamy fluid anymore.