PACCAR Incorporated (PACCAR) is recalling certain model year 2015 Peterbilt 367, 389, 567, 579, and 587 trucks manufactured from May 23, 2014, to February 13, 2015, and 2015 Kenworth T270, T370, T440, T470, T660, T680, T800, T880, and W900 trucks manufactured from May 23, 2014, to February 13, 2015, equipped with certain air brake actuators. The affected vehicles may experience brake drag due to an improperly seated diaphragm in the brake chamber.