2012 Mack LEU recalls

• Electrical#2017216April 19, 2017

  40 units affected

  Certain vehicles may have been built with an incorrectly sized alternator cable. This could potentially result in the cable overheating, which may increase the risk of a vehicle fire causing injury and/or damage to property. Correction: Dealers will replace the alternator cable.

• Powertrain#2016495October 11, 2016

  1,690 units affected

  On certain vehicles, the cap nut that retains the interaxle driveshaft yoke to the rear axle input shaft may prematurely loosen. If the nut were to loosen and come off, the yoke could separate from the axle input shaft and cause the drive shaft to disconnect. A disconnected drive shaft would result in a loss of motive power, and create a road hazard, both of which could increase the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect the torque on the cap nut, and the nut will be replaced if the torque is found under specification. Note: This is an expansion of recall 2016-079.

• Powertrain#2016079February 18, 2016

  1,068 units affected

  On certain vehicles, the cap nut that retains the interaxle driveshaft yoke to the rear axle input shaft may prematurely loosen. If the nut were to loosen and come off, the yoke could separate from the axle input shaft and cause the drive shaft to disconnect. A disconnected drive shaft would result in a loss of motive power, and create a road hazard, both of which could increase the risk of a crash causing injury and/or damage to property. Correction: Dealers will replace the cap nut, and inspect the threads on the input shaft. If the threads are damaged, the input shaft will be replaced.

• Engine#2015500October 23, 2015

  364 units affected

  On certain vehicles equipped with natural gas powered engines, the turbocharger oil supply line may make contact with or interfere with one or more of the following: the turbocharger inlet elbow, the OEM clean air intake clamp, or the air fuel control tube. The resulting contact or interference may damage the turbocharger oil supply line, possibly resulting in an oil leak. Oil leaking onto hot engine surfaces could increase the risk of a fire, and could increase the risk of injury and/or property damage. Correction: Dealers will replace the oil line.

• Engine#2015348July 31, 2015

  258 units affected

  On certain vehicles equipped with Cummins Westport ISL-G engines, excessive engine crankcase pressure could cause the vent tube assembly elbow to detach from the breather. This could allow engine oil to come in contact with hot surfaces, increasing the risk of fire resulting in injury and/or damage to property. Correction: Dealers will install clamps at both ends of the elbow of the breather tube assembly and reprogram the Electronic Control Module (ECM) to improve diagnostic capabilities.

• Lights And Instruments#2014146April 22, 2014

  5,990 units affected

  On certain vehicles, the directional/hazard signal flasher may fail. Actuation of the turn signal or hazard lights in this condition would cause them to remain illuminated and not flash as intended. As a result, drivers may not be able to clearly signal their intentions to turn, change lanes or warn others in an emergency situation. Correction: Dealers will replace the turn signal/hazard flasher module.

• Engine#2014090March 24, 2014

  157 units affected

  On certain vehicles equipped with Cummins compressed natural gas engines, incorrect engine ECU programming could cause the exhaust system temperature to become elevated during cold weather operation. This could also cause flames to be emitted from the exhaust. As a result, nearby combustible material could be ignited, increasing the risk of a fire, injury and/or damage to property. Correction: Authorized Cummins service facilities will update software programming.

• Engine#2014052February 21, 2014

  123 units affected

  On certain vehicles equipped with Cummins ISL engine, the exhaust pipe may disconnect from the muffler/catalyst. If this occurs on a twin-steer configured vehicle where the vehicle is operated from the right side, the operator may be exposed to carbon monoxide, which could result in asphyxiation or carbon monoxide poisoning. Correction: Dealers will install a different length exhaust flex pipe and a turbocharger outlet pipe to reduce rigidity of the exhaust to address this condition.

• Electrical#2012095March 8, 2012

  2 units affected

  On certain vehicles, the alternator ground cable was incorrectly installed during vehicle assembly. The incorrect connection defeats the intended electrical circuit protection. As a result, an electrical short could result in a vehicle fire causing property damage and/or personal injury. Correction: Dealers will disconnect the alternator ground cable from the starter and install it on the engine ground stud.

• Powertrain#2011205May 19, 2011

  584 units affected

  On certain trucks, the driveshaft may not have been welded correctly during the manufacturing process. This could allow the driveshaft to fracture along the length of the tube seam weld when torque is applied. The fractured tube can twist or sever, which could result in additional damage to the driveline, the vehicle to which it is attached, and any additional nearby components. Should the brake air lines become damaged, it could allow spring brake application, causing immediate brake lock-up. If this occurs while the vehicle is in motion, it could result in a crash. Also, failure of the driveshaft would result in lost vehicle propulsion which, in conjunction with traffic and road conditions, and the driver's reactions, could increase the risk of a crash. Either condition could result in property damage and/or personal injury. Correction: Dealers will replace the driveshaft assembly.

• Brakes#2011182May 2, 2011

  329 units affected

  On certain vehicles, the slack adjuster housings may have been manufactured incorrectly, which could allow the housings to fracture and fail. As a result, the wheel brake to which the slack adjuster is attached would no longer function, which could increase vehicle stopping distances. Should a steer axle slack adjuster fail, it could also cause the vehicle to pull to one side during braking. Either problem could result in a crash causing property damage and/or personal injury. Correction: Dealers will inspect and, if necessary, replace the slack adjusters.

• Electrical#2011148April 1, 2011

  109 units affected

  On certain vehicles, the rearview mirror switch (mounted on the dashboard) may overheat, causing the plastic to melt. An overheated switch may not allow rearview mirror remote adjustability and, as such, the driver may not have full use of the mirrors. In addition, excessive heat can cause smoke within the instrument panel, which could distract the vehicle operator and result in a crash causing property damage and/or personal injury. Correction: Dealers will inspect the rearview mirror switch and install a relay wiring harness. Switches that show signs of overheating will be replaced.

Canadian data updated August 24, 2026

• ENGINE AND ENGINE COOLING:ENGINE#15V275000May 11, 2015

  Mack Trucks, Inc. (Mack) is recalling certain model year 2011-2016 Mack MRU and LEU trucks manufactured June 25, 2010, to April 30, 2015, and 2015-2016 LR6 trucks manufactured from December 18, 2014 through March 6, 2015. Excessive engine crankcase pressures may cause the 90-degree elbow of the vent tube assembly to detach from the crankcase ventilation breather, possibly allowing engine oil to come into contact with hot surfaces.

  Risk: If engine oil comes into contact with a hot surface, there could be an increased risk of a fire.

  Remedy: Cummins will notify owners on behalf of Mack, and Cummins service centers will administer the repairs which include 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. These repairs will be performed free of charge. The recall began on June 12, 2015. Owners may contact Mack customer service at 1-800-528-6586 or Cummins Inc. at 1-800-343-7357. Mack's number for this recall is SC0391.

• EXTERIOR LIGHTING:TURN SIGNAL:FLASHER UNIT#14V208000April 18, 2014

  Mack Trucks Inc. (Mack) is recalling certain model year 2010-2014 CHU, CXU, and MRU, 2007 CT and CV, 2008-2014 GU, and 2011-2014 LEU, and TD trucks manufactured February 28, 2006, through November 8, 2013, and equipped Hamsar Electronic Flasher. The hazard warning lights may fail.

  Risk: A failure of the hazard warning lights could reduce the trucks visibility, increasing the risk of a crash.

  Remedy: Mack will notify owners, and dealers will replace the electronic flasher unit, free of charge. The recall will begin by mid-June 2014. Interim letters went out to owners on June 23, 2014. The recall began on July 25, 2014. Owners may contact Mack customer service at 1-866-298-6586. Mack's number for this recall is SC0379.

• ENGINE AND ENGINE COOLING:ENGINE#14V137000March 24, 2014

  Mack Trucks Inc. (Mack) is recalling certain model year 2014-2015 CXU, 2010-2015 LEU, and 2011-2015 MRU vehicles manufactured with certain Cummins Westport Model ISL G and ISX12 G engines. Condensation in the intake manifold may freeze during cold weather conditions and interfere with the proper operation of the intake manifold pressure sensor.

  Risk: The improper operation of the sensor could induce elevated exhaust temperatures or flames from the exhaust pipe, increasing the risk of a vehicle fire or burn injury to a person near the exhaust pipe.

  Remedy: Cummins and Cummins Westport will notify owners, and authorized Cummins service facilities will upload a new ECM calibration, free of charge. The recall began on March 12, 2014. Customers may contact Mack at 1-336-393-2000 or Cummins Inc. at 1-800-343-7357. Mack's number for this recall is SC0377.

• ENGINE AND ENGINE COOLING:EXHAUST SYSTEM#14V088000February 21, 2014

  Mack Trucks, Inc. (Mack) is recalling certain model year 2010-2015 LEU vehicles manufactured May 14, 2009, through February 14, 2014, and equipped with a Cummins ISL engine. In the affected vehicles, the exhaust pipe may disconnect from the muffler/catalyst.

  Risk: If the exhaust pipe separates from the muffler on a twin-steer configured vehicle where the vehicle is operated from the right side, the operator may be exposed to carbon monoxide levels which may cause personal injury.

  Remedy: Mack will notify owners. The recall began on April 21, 2014. The recall is expected to begin in late April 2014. Owners may contact Mack Trucks at 1-336-393-2000. Mack's number for this recall is SC0376.

• ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR#12V096000March 8, 2012

  MACK IS RECALLING CERTAIN MODEL YEAR 2010-2012 LEU AND MODEL YEAR 2011-2012 MRU VEHICLES, MANUFACTURED FROM MAY 14, 2009, THROUGH OCTOBER 31, 2011, AND BUILT TO OPERATE ON COMPRESSED NATURAL GAS. ON THESE VEHICLES THE ALTERNATOR GROUND CABLE RUNS DIRECTLY TO THE STARTER, WHICH DEFEATS THE CIRCUIT PROTECTION.

  Risk: IN THE EVENT OF AN ELECTRICAL SHORT, A VEHICLE FIRE MAY RESULT.

  Remedy: MACK WILL NOTIFY OWNERS, AND DEALERS WILL RELOCATE THE ALTERNATOR GROUND CABLE TO THE ENGINE GROUND STUD. THIS SERVICE WILL BE PERFORMED FREE OF CHARGE. THE RECALL BEGAN ON APRIL 19, 2012. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-866-1177.

• POWER TRAIN:DRIVELINE#11V295000May 20, 2011

  MACK TRUCKS IS RECALLING CERTAIN MODEL YEAR 2012, CHU, CXU, GU, MRU, LEU, AND TD TRUCKS EQUIPPED WITH A MERITOR DRIVELINE. THE TUBING USED TO ASSEMBLE THE AFFECTED DRIVELINES HAS A NONCONFORMING SEAM WELD WITH INSUFFICIENT BONDING OF THE MATERIAL.

  Risk: THIS CAN RESULT IN SEAM WELD FRACTURE WHEN TORQUE IS APPLIED. ONCE THE TUBE SEAM WELD IS FRACTURED, THE DRIVELINE MAY BECOME INOPERABLE WHICH MAY RESULT IN A DISABLED VEHICLE OR DEBRIS FROM THE DRIVELINE MAY FALL ON THE ROADWAY, BOTH OF WHICH CAN INCREASE THE RISK OF A CRASH.

  Remedy: DEALERS WILL REPLACE THE DRIVELINES FREE OF CHARGE. THE SAFETY RECALL BEGAN ON JULY 25, 2011. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-528-6586.

• SERVICE BRAKES, AIR:SLACK ADJUSTERS:AUTOMATIC#11V272000May 3, 2011

  MACK TRUCKS IS RECALLING CERTAIN MODEL YEAR 2011-2012 CHU, CXU, GU, LEU AND MRU TRUCKS MANUFACTURED FROM OCTOBER 15, 2010, THROUGH JANUARY 31, 2011, AND EQUIPPED WITH GUNITE AUTOMATIC SLACK ADJUSTERS. DUE TO AN INCOMPLETE "KNITTING" OF THE IRON AT THE TIME OF CASTING, INADEQUATE STRUCTURAL INTEGRITY OF THE SLACK ADJUSTER HOUSING CAN OCCUR, WHICH COULD CAUSE THE HOUSING TO BREAK AT THE HANDLE UNDER NORMAL OPERATING LOADS.

  Risk: SLACK ADJUSTERS WITH THIS FLOW NOTCH COULD CRACK UNDER NORMAL BRAKING CONDITIONS CAUSING LOSS OF BRAKING WHICH COULD RESULT IN A VEHICLE CRASH.

  Remedy: MACK TRUCKS WILL NOTIFY OWNERS AND DEALERS WILL REPLACE THE SUBJECT SLACK ADJUSTERS FREE OF CHARGE. THE SAFETY RECALL BEGAN ON AUGUST 24, 2011. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-528-6586.

• ELECTRICAL SYSTEM#11V212000April 1, 2011

  MACK TRUCKS IS RECALLING CERTAIN MODEL YEAR 2008-2012 MRU AND LEU HEAVY TRUCKS MANUFACTURED FROM JANUARY 3, 2007, THROUGH FEBRUARY 3, 2011. THE ELECTRICAL CIRCUITRY IN THESE VEHICLES MAY NOT PROVIDE ADEQUATE OVERCURRENT PROTECTION.

  Risk: IN THE EVENT OF AN ELECTRICAL OVERAGE, THE FUSE THAT SHOULD PREVENT THE OVER CURRENT FROM REACHING THE MIRROR SWITCH CIRCUIT MAY FAIL, SUCH THAT THE MIRROR SWITCH CAN OVERHEAT. AN OVERHEATED SWITCH COULD CAUSE A VEHICLE FIRE.

  Remedy: DEALERS WILL INSTALL A RELAY HARNESS TO PREVENT THE MIRROR SWITCH FROM OVERHEATING. THEY WILL ALSO INSPECT THE MIRROR SWITCH AND IF SIGNS OF OVERHEATING ARE SHOWN, REPLACE THAT SWITCH. ALL INSPECTIONS AND REPAIRS WILL BE PERFORMED FREE OF CHARGE. THE SAFETY RECALL BEGAN ON JUNE 30, 2011. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-866-1177.