All the rotors I've ever gotten were coated in cosmoline (grease, for those who aren't familiar with it).

If they are primered (dry coating, not slimy), it will wear off immediately. Cosmoline (greasy stuff) will, too, but only after you've crashed the car from greased brakes.

I always rough the rotors with some coarse sandpaper, too -- this keeps the pads from "groaning" as you come to a stop.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!