I recently purchased a 2000 F250 7.3L and I am having some trouble diagnosing a problem. At low speeds it is quite difficult to turn and makes a small whining sound. At first, I was sure that the power steering pump was bad, but now I am not so certain. I started it up in the driveway and had someone turn the wheel to see if I noticed anything else going on. When the wheel is turning, it looks like the cap on the power steering reservoir is trying to come off. It looks like there is pressure building up in the pump. Any advice on where to start? Or what else to look for to further diagnose the problem? Thanks.

 

I would certainly look for pinched lines or any physical damage, and then replace the power steering fluid through multiple siphonings (running the truck between each).

After that, I'd replace the pump. Ford pumps do fail, and low boost and moaning are typical signs of a worn pump.

 

This is typical since the brake booster and p/s box are fed from the same pump. There are a few discussion about this, and I have noticed it depends on the pump. A different pump won't always fix the problem. I've had four or five pumps on mine some better than others. The first pump I had was noisy when cold but worked great. If figured my setup didn't have the low power steering issue. I changed out the pump to get rid of the noise and had trouble with low speed on the brakes steering. The next pump didn't do any better and trying to flush out the system didn't help. Pump failed, and the 4th pump I drilled out the orifice in the regulator valve some and have no problems with steering now, unless i am hard on the brakes. If your fluid is good, clean ATF (some even switch to synthetic) then I would suspect a weak pump. Drilling out the orifice may help.

 

so where is this oriface that needs to be drilled out and how big? my truck also wont turn at low speeds. i also had an issue of brakes failing a while back that i feel may have been related to this problem. im scared to fool with this system because of that. any help would be greatly appreciated! thanks