2001 Tahoe Power Steering

I was pulling into a parking spot today and the power steering on my 2001 Tahoe totally stopped working. I can steer, but have no power steering. Very difficult to turn. Both left and right. There were no warning signs. No sounds. And it did not gradually lose power. It was very sudden. I checked the fluid. was on full/cold (but engine was warm) so I topped it off. No help. drove for 30 miles or so and still no power.

Where do I start? Will take to dealership if needed. Any ideas or help is appreciated.

Ditto, I have a 2001 Tahoe and the same thing just happened this past week, no signs of trouble and full of fluid. Wonder what the problem is then? Any help.

It was the power steering pump. Had it replaced...no more problems