Easy power steering fluid flush method on w124s
 

P/S fluid flush on w123s is quite easy by removing reservoir fluid return hose and flushing old fluid into bottle as you add new. On the 400E however, this fitting and hose was solid tubing with very limited access to fitting fasteners.

After diligent search here and other places for proper method and finding none, I improvised. Solution that worked for me was after removing fluid in reservoir by suction (and filter of course), I simply inserted 3/8 inch (approx.) clear plastic tubing into cavity where return line entered reservoir and this (b/c of tight fit) allowed fluid to be returned into bottle instead of reservoir in the same way as W123 method.

Hope this helps anyone that needs to do this with filter change (which is everyone with more than 30K on their car who hasn't already).

I, of course, don't have to worry about this on the 67 Finny 200D that I got today, it has no power steering.