Vehicle is an '01 7.3 PSD.

When turning the wheel (all the time), I hear what sounds like a groaning or moaning noise. I think it is the pump. Besides a stethoscope, how could I narrow this down.

My truck made the same noise, flushing the old dirty fluid out and putting new in basicly cured it, most trans flush machines also do power steering fluid.

Brewchief:D