SERVICE BRAKES, AIR:ANTILOCK
Mack Trucks, Inc. (Mack) is recalling certain 2010-2018 MRU and 2019-2025 Terrapro towing vehicles. The vehicles are missing the anti-lock brake (ABS) warning light and circuitry that controls the anti-lock brake function for an attached trailer. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 121, "Air Brake Systems."
Remedy: Dealers will add an ABS warning light and circuitry, free of charge. Owner notification letters were mailed April 28, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0474.
142 vehicles affected
ENGINE AND ENGINE COOLING:ENGINE
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.
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.
2,124 vehicles affected
EXTERIOR LIGHTING:TURN SIGNAL:FLASHER UNIT
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.
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.
44,047 vehicles affected
ENGINE AND ENGINE COOLING:ENGINE
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.
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.
1,934 vehicles affected
ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR
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.
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.
318 vehicles affected
SUSPENSION:FRONT
MACK IS RECALLING CERTAIN MODEL YEAR 2009-2011 MRU AND MODEL YEAR 2010-2011 LEU VEHICLES, MANUFACTURED FROM JANUARY 1, 2009, THROUGH SEPTEMBER 30, 2010 BECAUSE THE FRONT AXLE MAY CRACK AND FRACTURE.
Remedy: MACK WILL NOTIFY OWNERS, AND REPLACE THE AXLE BEAMS ON AFFECTED VEHICLES WHEN SUFFICIENT QUANTITIES ARE AVAILABLE. AS AN INTERIM MEASURE, A MAG PARTICLE INSPECTION WILL BE PROVIDED TO MITIGATE RISK AND IDENTIFY VEHICLES WITH CRACKED AXLE BEAMS. THIS SERVICE WILL BE PERFORMED FREE OF CHARGE. THE SAFETY RECALL BEGAN MARCH 30, 2012. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-866-1177.
4,032 vehicles affected
STEERING:GEAR BOX:SHAFT SECTOR
MACK TRUCKS IS RECALLING CERTAIN MODEL YEAR 2009-2012 MRU HEAVY TRUCKS MANUFACTURED FROM NOVEMBER 26, 2008, THROUGH APRIL 26, 2011. THE BOLTS USED TO MOUNT THE STEERING GEAR WERE NOT TIGHTENED TO SPECIFICATION. THE BOLTS CAN LOOSEN WHICH OVER TIME MAY CAUSE THE STEERING GEAR TO DISCONNECT FROM ITS MOUNTING BRACKET.
Remedy: DEALERS WILL REPLACE THE BOLTS, WHICH WILL BE TIGHTENED TO THE CORRECT SPECIFICATION. THIS SERVICE WILL BE PERFORMED FREE OF CHARGE. THE SAFETY RECALL BEGAN ON SEPTEMBER 19, 2011. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-866-1177.
2,294 vehicles affected
SERVICE BRAKES, AIR:SLACK ADJUSTERS:AUTOMATIC
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.
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.
1,524 vehicles affected
ELECTRICAL SYSTEM
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.
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.
3,763 vehicles affected
SERVICE BRAKES, AIR
MACK IS RECALLING CERTAIN MODEL YEAR 2008 THROUGH 2011 GU AND MRU MODEL VEHICLES MANUFACTURED WITH A FRONT TOW GLAD HAND OPTION. THE ACTUATION AND RELEASE TIMING OF THE VEHICLES EXCEEDS THE LIMIT WHICH FAILS TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121, "AIR BRAKE SYSTEMS."
Remedy: MACK WILL NOTIFY OWNERS AND REPAIR THE VEHICLE FREE OF CHARGE. THE SAFETY RECALL BEGAN ON FEBRUARY 1, 2011. OWNERS MAY CONTACT MACK AT 1-877-800-4945.
369 vehicles affected