since there was some comments about ceramic pads, i found this article interesting. By the way brake pads has got nothing to do with the rust on the disc
[SIZE=+1]Ceramic Brake Lining Material[/SIZE]
Although first introduced as far back as 1985 on some new vehicles, mass aftermarket applications for ceramic-based disc brake pads are just now becoming widely available. Approximately 33 percent of all new vehicles, domestic and foreign combined, now have ceramic-based disc brake pads. The newest generation of ceramic brake lining compounds contain no chopped steel fibers or steel wool as found in earlier semimetallic linings, but instead substitute ceramic compounds and copper fibers. These changes provide modern ceramic-based lining materials the capability of handling today's high brake temperatures with less heat fade, faster recovery time, and less wear on both the pads and rotors.
Of even more value to brake repair facilities is the ability of ceramic lining compounds to significantly reduce annoying brake noise or squeal, which is the No. 1 consumer complaint relating to brake service. Ceramic compounds dampen noise and move brake pad vibrations to a frequency outside of our human hearing range, 20 Hz through 20,000 Hz. As with earlier disc brake pad designs, some ceramic pad applications may also incorporate other noise-reducing features such as chamfers, slots and insulator shims. One leading aftermarket manufacturer has gone as far as naming its line of ceramic brake pads "Quiet Stop."
Another positive characteristic associated with ceramic brake lining materials is the absence of visible brake dust, a feature that any vehicle owner with stylish wheels will appreciate. All brake materials, ceramic included, will produce some brake dust. Earlier semimetallic and organic brake compounds left a brownish black dust on wheels. In comparison, ceramic compounds produce a light-colored dust that is much less noticeable and does not attach itself to wheels.
Although an increase in product cost will more than likely be associated with ceramic-based brake linings, their benefits may be worthwhile for consumers. Based on their own durability tests, lining manufacturers say these compounds will outlast most other premium pad materials by a considerable margin. However, aftermarket brake pads with ceramic materials should only be used on those applications where the OEM specified a similar formula.
http://www.godfreyhallshrpshirebmw.co.uk