Thanks for the replies. So the filter just sits at the bottom of the resevoir? Any ideas on how much fluid I should buy? My car did not have an owner's manual in it when I bought it, so I don't know whether to use "power steering" fluid or ATF.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member