I Have been trying to replace the B-2 Piston in my 1983 300SD but I have ordered the wrong part twice. Could anybody out there tell me what the part name is for the BLACK seal that fits over the piston sleeve, NOT the red o-ring. I have looked all over and called Fastlane but they sent me the wrong part.
I am going off to college in less than a month and I have to have the car back on the road by then.

006 997 73 47
Is for the inner rubber lip seal that seats against the bushing. I believe that is what you are looking for.

This thread should have all the parts numbers and a couple of links that are useful.
Good luck.
B2 piston Cover blow out! (Long Post)