Power steering leak - 99TL - power steering speed sensor

I have a 99TL with 232K miles. I have had a small power steering leak for about a year. I just fill the reservoir every month or so it's a few tablespoons of fluid to the high mark. I took the photos in the links below of the power steering speed sensor and repair manual on the subject. It looks difficult to reach as it is installed in the very back of the transmission. I've not noticed any problem with stearing the vehicle, and am interested in whether anyone has replaced one. Alternatively, is this a typical place for fluid to leak from? I checked where the high-pressure power steering line goes into the rack and pinion steering, and it is not leaking there.
https://www.flickr.com/photos/47004606@N00/14844742631/
https://www.flickr.com/photos/47004606@N00/14824841166/
https://www.flickr.com/photos/47004606@N00/14661281037/