Steering box leaks

[Water Boy]

While was changing the oil I thought I would check the power steering fluid (PSF) level. It was OK.

A short time later I had a large puddle of PSF was under the steering box (SB). It appeared to be coming out the top of the SB. Then it quit leaking.

So, my thought is the seal is bad on the SB and after is leads some it creates a vacumn. When I opened the PSF tank it broke the vacumn, thus the puddle.

Should I fix?

Right now, when I fill up the gas tank, the value $$$ of my '90 doubles.