Mack Trucks is recalling 2,124 Mack MRU and LEU (TerraPro) trucks in the 2011-2016 model years, as well as LR6 trucks in the 2015 and 2016 model years, because potential engine-cooling problems might pose a fire risk, the National Highway Traffic Safety Administration reported.
These trucks, commonly used for refuse collection and construction applications, have Cummins Westport ISL G natural gas engines. Excessive engine crankcase pressures might cause the 90-degree elbow of the vent tube assembly to detach from the crankcase ventilation breather. As a result, engine oil might come into contact with hot surfaces and create a higher risk of fire, NHTSA said.
Conditions contributing to high engine crankcase pressure also have the potential to trigger a loss of engine power, illuminate amber or red engine diagnostic lamps on the vehicle instrument cluster, or result in erratic engine operation.
The Mack MRU and LEU trucks at issue were manufactured from June 25, 2010, to April 30 of this year. The LR6 trucks were manufactured from Dec. 18, 2014, through March 6 of this year.
Cummins Inc. will notify truck owners of the recall on behalf of Mack, and Cummins distributors or authorized warranty dealers will make the necessary repairs. These repairs involve securing the ends of the 90-degree elbow and reprogramming the electronic control module (ECM) with software that can adjust the engine output under misfire conditions to limit crankcase pressures.
There will be no charge for these repair services.
Truck owners can reach Mack customer service at (800) 528-6586 or Cummins at (800) 343-7357. Mack's number for this recall is SC0391.