The No. 1 job of truck brakes is safety; within that application, there’s more than one way to stop a truck. Drums have been the brake of choice for many trucks, but air disc brakes (ADBs) continue to gain popularity in nearly all heavy-duty on-road applications.

“Current [ADB] market penetration is in the 12% to 15% range for power units and 8% to 10% for trailers,” said John Thompson, sales manager CV NAFTA, for TMD Friction, supplier of commercial vehicle brake friction, brake pads and linings to both the OE and aftermarket sector. “Installations are increasing and it is currently believed that penetration will level off in the 20% range in the next five years. Some OEMs are standard with steer axle disc brakes, and upcharges for spec’ing disc brakes have reduced somewhat. These trends, coupled with improved performance over cam brakes, will help increase market penetration.”

Fleet Equipment talked to the top minds in the brake and friction markets to get the answers to the most asked brake spec’ing questions.