The brake rotor wearing away the brake lining causes brake dust. Brake pads are made of carbon fibers, metal filings and adhesives. Adhesive is acidic in nature and will cling to the metal filings while they are hot, causing the concoction to singe the wheel surface. The dust tends to be tacky and builds up in every tiny crevice on your wheels. Brake dust can damage your wheels if not removed and becomes especially difficult to remove once it bakes on. The only way to avoid such a catastrophe is to clean your wheels often, removing all brake dust.
Fill a bucket with water. Wet the wheels with water from the bucket or a hose. Scrub the wheel gently but firmly with a wheel brush to remove any loose brake dust or debris.2
Spray brake or wheel cleaner on the wheel, avoiding the tire. As per the instructions on the cleaner, begin scrubbing the wheel to remove residual brake dust.3
Rinse the wheel completely with water to remove any cleaner. If brake dust remains, you may need to clean the wheel again. Brake dust left on the wheel can bake on and will be difficult to remove. Using a stiff wheel brush and strong force may be necessary to loosen the dust.4
Use an old toothbrush or a small wheel detailing brush to get into small spaces, as a final cleaning may be needed to remove brake dust from small cracks, crevices and divots. Spray brake dust remover onto these areas and brush out. Cotton swabs can get into tiny spaces. Ceramic brake pads will lessen the amount of brake dust, although not completely. Top of the Line Detailing Supplies' solution is to keep the brake dust off the wheels. Cleaning your wheels thoroughly each time you wash your car will keep brake dust at bay and possibly prevent it from becoming baked on altogether.