Patsy, I'll have to look at it more closely. I plan on sucking out the old fluid with a turkey baster and replacing it with new p/s fluid. When I do this I should see a line of sorts. I have concluded that my p/s sys. has p/s fluid, not ATF, in it. I bought a bottle of p/s fluid and it's gold in color, like the fluid in my reservoir.
1999 MB SL500 (101,000 mi)
1983 Porsche 911SC (149,000 mi)
2004 Volvo V70 2.5T (205,000 mi)
2014 Tesla Model S 85 (75,000 mi)