power steering???

[190E-Bpy]

pump or fluid.

I'm a noob to the E300 world. I've owned it for the past 3-4 months
and I'm getting a noise when I turn my wheel, almost like a tire rubbing
on the curb, but only when I'm stopped or barely moving. If I give it more fuel
and turn it becomes less obvious and not noticable while I'm driving making turns at 30+ mph.

1. What should my power steering fluid look like? Color? Amount? Am I looking in the right cap? (I know where the brake fluid goes) so by process of elimination the little black cap is the one I'm inspecting.

2. Where should it be on the guage?

3. How full should the resevoir be?

4. Is it more likely my pump gone bad?

5. Or am I barking up the wrong tree all together?


thanks
ps its a 1996 E300 Diesel