2001 S40 Unknown part leaking

[williamregan]

There is a black round part a few inches in front of the power steering filler/reservoir that is leaking on my car. It's about 4 or 5 inches in diameter and is about 4 inches high. There is some brown fluid leaking out of the front base of this part. There is no apparent power steering leak.

What is this part and how can I fix the leak?

Thanks, Bill