Does one need to remove grey coating from surface of new E500 brake rotor
Installing new brake rotors on E500. Notice that they are coated in dull grey finish, that is no metal is exposed.
I tried to rub it off using mineral spirits type solvent. Didnt work. Do I actually need to remove the finish before installation? If so, do I need to remove from the entire rotor, ie hub mounting area etc? What should I use to remove it.
Is the grey substance an anticorrosion protectant ?
Thanks and regards
1994 E500 53K miles - triple black
1995 E320T 60K miles, Starmark, E500 suspension upgrade