Humming while steering

I am new here.

I have a 1997 Mercury Mountaineer AWD 5.0L. We recently rebuild a lot of the parts and one was the power steering pump. Finished it a few weeks ago and all was good. Just a few days ago it started making a horrible humming sound in when turning and accelerating. I trying to bleed air out of pump by turning wheels all the way over and back and sound got better when I was doing it but then when I started to drive sound came back. Fluid in resevoir is full. Any suggestions or comments?

Jason

You might try the steps suggested in this post.

-Rod