Each successive layer of black dust on those shiny alloys = brake job. The empty weight on B.O.U.R.G’s truck is 4800 lbs. and depending on useage those front pads can convert to black dust in as little as 10,000 or as long as 40,000 miles. Friction products are primarily a combination of calcium carbonate, rock wool, various resins, steel wool, brass filings, silica, and fiberglass and a few other odds and ends. luckily they don’t incorporate ASBESTOS anymore, but still one wonders about the long term effects when aspirating this carcinogenic brew. Not all of it clings to the wheels. Where does it all go? I could let the authori$ed $ervice fa$ility renew my brakes or or how about a do it yourself. I will be sure to wear a filter mask.