Daimler Trucks North America (DTNA) is recalling certain model year 2011 through 2013 Thomas Built non-school buses manufactured from March 2010 through July 2012, equipped with Cummins ISB6.7 diesel engines manufactured from February 16, 2010, through May 4, 2012, containing a fan pulley, part number 3914462. The subject fan pulley is part of the accessory drive system on the front of the engine. This system is used to drive such components as the refrigerant compressors, the radiator fan, and the engine water pump. The web of the pulley can fatigue over time, causing the pulley to fail.