FYI both those tanks have integrated filters and are considered service items,
you can buy them online new for like 23 dollars.
The filter is good for about 12000 miles depending on your driving habits.
Sorry was distracted from the web for a while,, yep on a BMW you
throw the whole reservoir away when you service the system.
They are cheap to buy, hate the waste though. Pelican parts is where I get mine.
I find by 12K that the filter is shot, I've dumped the system and
refilled and the fluid turns black almost instantly.
They hold so little fluid a cooler is mandatory. BMW's don't use
power steering fluid they use Type F auto transmission fluid. (Trivia :) )
I'm swapping out the throwaway unit for a aftermarket AL tank with a spin-on filter.
My car is AWD and works the heck out of the power steering.