300E steering noise
 

Ok, here's the latest issue with my car (1986 300e):

Almost every time I turn right, my car makes a noise. The noise is like a loud humming (kind of like a power steering pump without any fluid). I turn left, and nothing happens. The noise occurs more frequently when the turns are sharper. Does this sound like the power steering pump to you too? Why only right turns? Is there a possible clog or pinch that is aggravated by the turn to the right?

The power steering pump is full of OEM fluid.

Thanks!
Paul