58k miles and my steering is humming. If the fluid is low, I'd question where the leak is (as it's sealed system). Could the power steering box die at this age?

 

Do you recognize the song? (get it, humming? Ha ha)

When doe it make sound? Doing at idle, on highway or only when turning?

With the plastic cover under the front, you don't always see leaks when they first start.
Have you check the power steering fluid level?

 

Where is the humming coming from? It could just your tires. Is it all the time, only on the highway, etc...

 

If the fluid level is normal and there isn't any leak, check your power steering pump. Any part can fail at any age.

 

The humming occurs at low RPM's, primarily in parking lots. As the throttle increases the humming increases in hertz/frequency. It get's "whinier".

 

I have the same issue. My power steering rack is leaking so I think the humming is coming from that.