twalgamuth said,
Just because they have anti lift features in the design does not mean it actually dips under braking.

My 280S surely dipped in the rear end under normal braking conditions.

I still suspect it has to do with the greater gripping power of the organic brake pads that were on these cars when new. So, I decided to see if the organic pads were still available. Organic brake pads are known for their "high initial brake effect," according to Summit Racing. CAll it, "getting ahead of the dip."

T, have you tried organic pads, or did you switch to ceramic to avoid the extra dust? If you did, you did at least one thing to change the dynamics of your rear suspension. Did you put on heavy duty shock absorbers? If you did, you changed the dynamics of your rear suspension. Did you replace your rotors with the same ones Mercedes used in the eighties? Doubtful, so you have changed the dynamics of your rear suspension. If I remember correctly, MB used cast iron rotors, which also may not be around any more. Cast iron would also create a "high initial brake effect," to get ahead of the dip.

So, let's talk about rotors. These cars likely had cast iron rotors when they came out. Brembo states that, cast-iron, "chosen for its superior friction coefficient, high-heat and moisture-absorbtion capabilities." Brembo also no longer makes cast iron rotors. While Brembo is relating this to motor cycles, the technology timeline was similar for cars.

Brembo Rotors

So, what do you have in your car? It is likely a carbon steel rotor, which lasts longer and rusts less easily, BUT, it does not have as high a friction coefficient. Carbon fiber and carbon steel is used today as they have less weight.

So, if you thought you brought your car "up to specs" because you went to J. C. Whitney and bought the latest in ceramic pads and carbon steel rotors, I will tell you that your brakes are only about 75-90% of what they were when new. My guess is that your brakes are more like 75% functional when compared to a car coming off the showroom floor. It takes more pedal power to stop my 1983 240D than the cars I owned new back then, and my master cylinder has an extra 1/16 to 1/8 of an inch bore.

And, I checked again. My rear rotors are still behind the axle.