Do you remember a guy named Newton? Remove the reservoir, empty it, and clean it thoroughly. Fill both compartments with fresh fluid, and open each bleed screw slightly until clean clear fluid comes through. You will almost always see bubbles, but that isn't air in the system. It is air being syphoned in by the open bleed screw. This won't work with drum brakes, but always works with discs. Some cars require a sequence of calipers, but not MB. The law of gravity is very simple, and no trial lawyers are needed. You can buy a bleeder if you are compelled to, but gravity has worked for me as a professional mechanic for three decades. Also, the reason for a split reservoir is safety. The front brakes on MB cars have been historically been supplied by the rear chamber, and the front chamber supplies the rear brakes. If you loose all the fluid in one circuit for some reason, you still have brakes in the front or back.
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