Want to feel a little less safe around 18-wheelers on the highway? Consider most of them are using drum brake technology abandoned by the automobile industry decades ago.
New federal regulations on stopping distance are driving truck manufacturers to seek new braking technology that could see semis outfitted with big disc brakes, kind of like overgrown, air-powered versions of the disc brakes that likely stop your car. According to FleetOwner, the manufacturers have been experimenting with air disc brakes– also known as ADBs– and finding a number of benefits and challenges.
While disc brakes can dissipate heat more easily than drums, for example, the article pointed out that coming regulations in some states about the content that makes up disc brake pads may cause the brakes not to perform as well as they do with current pads, or may make servicing those brakes prohibitively expensive. Despite the concerns, some truck manufacturers have ruled it worthwhile. Peterbilt started making ADBs standard on the steer axle of its Class 8 heavy trucks last year, the article said.