I have got a 2001 f150 xlt 4.6L with about 120k miles on it. Everything was fine the day the problem started. I was turning into my grandmothers driveway which entailed me turning the wheel all the way to the right. When I went to straighten the wheel, I got a hellish high pitched whine when i put pressure on the wheel to turn it.

So I shut the truck off, to inspect under the hood and didnt see anything that caught my attention. So i started the truck and it whined without me even putting pressure on the wheel in any direction. Checked my fluid level and the PS fluid was below minimum. So i topped it off, turned the wheel a few times and the problem seemed to go away.

Now, however, the power steering will only seem to work when im accelerating and even then, i can feel pressure against my turn in the wheel, and a little jerkyness but sometimes it drives like theres no problem at all. Although at a stand still the power steering seems to not exist.

I have not noticed any leaks in my line or anything similar. I was wondering if my power steering pump may be going out, but ive also heard people mention the rack and pinion. Any help would be appreciated. Also if anyone can let me know if driving it in this condition is detrimental to the truck in anyway that would be great

 

I have this EXACT same problem with my 2008 f150. I had the pump and rack replaced. worked fine for a month or so then returned. But like you said, when accelerating its fine, and at a stand still it basically isn't there. Have you resolved these problems yet, and if so how? Any input would help as I've already dished out $1000 on replacing the rack and pump and can't afford to do that again.

 

Did you use power steering fluid or mercon transmission fluid? Either way, sounds like the pump crapped out.

 

The problem was with the pulley itself. The pulley was plastic attached to the metal ring inside the center. The metal center attaches to the rod on the power steering pump itself.

The plastic pulley came un-attached from the metal ring. In other words when i pulled the pulley off, I could hold the center metal part (the part that pushes onto the power steering pump) and the pulley would spin freely around it.

So basically when the pulley is on the pump and the belt is spinning the pulley, the pulley is spinning but it isnt spinning the rod on your pump.

The reason it works when you accel, is bc the belt is spinning fast enough to spin the rod on the pump and the pulley, but when you idle, the pulley just spins freely at least I finally found out that was the problem for me once it quit completely and my belt snapped.



Take the belt off of the power steering pump and see if your pulley is loose. Wiggle it front to back (pertaining to the car) and spin to see if there is any resistance. If you can spin it like the wheel in wheel of fortune (bad example lol) then you had the same problem i did. The plastic pulley broke away from its center part.

I hope this helps, I never thought to post a reply that I figured out my problem, however Ive gotten a new pulley and everything works great now!

 

I'll have to see if this is the problem I'm encountering too. Thanks for replying so soon. Ill check tomorrow morning and see if that's it. I'll post up again letting y'all know how it goes. Wish me luck.

Thanks, Dalyan