~One manâ€â„¢s opinion / observations~
Brake dust:
Particles produced from the friction of brake pads rubbing against the rotor (note: some contain asbestos). This metal on metal friction disperses tiny particles of black dust, which adheres to the wheel. The front wheels are usually more soiled, as this is where most of the vehicle braking effectiveness is.
For badly soiled surfaces use an undiluted citrus-based APC (P21S Total Auto Wash), then use detailerâ€â„¢s clay followed by a gel-type neutral pH wheel surface cleaner (P21S Gel Wheel Cleaner). Due to the friction heat transferred from the rotors (175oF+) apply a polymer surface protection as it has a higher melting point than wax (130-180oF) this will also ensure easier future cleaning (Klasse All-In-One)
Sequestered brake dust, if left for any length of time on the wheelâ€â„¢s causes galvanic corrosion, which etches the surface and eventually dulls the wheelâ€â„¢s appearance if not removed on a regular basis. To remove brake dust stains use a mildly abrasive cleaner (Iz Einszett® Metal Polish "Chrompflegeâ€Â�, P21S Multi-Surface Finish)
~Hope this helps~
Knowledge unshared is experience wasted [each one / teach one]
justadumbarchitect / so I question everything/ JonM