Daimler Trucks North America recalled 8,622 heavy-duty trucks and buses to check for loose brake caliper bolts, as well as electrical and natural gas defects that could cause fires.
The maker of Freightliner and Western Star trucks told the National Highway Traffic Safety Administration that it is not aware of any injuries, crashes or fires related to the defects.
The largest recall covers 7,066 trucks and buses. Insufficiently tightened brake caliper mounting bolts may have been on 2018-2019 Thomas Built Saf-T-Liner C2, Saf-T-Liner HDX and Saf-T-Liner EFX school buses. The same condition may affect 2018-19 Freightliner 108SD, 1145D, Cascadia and Business Class M2, and Western Star 4700 and 5700 models.
The loose bolts may provide inadequate clamping force between the caliper and the brake anchor plate. That could reduce brake effectiveness and lead to a crash. Daimler estimated that 1 percent of the recalled trucks may have the defect.
In September, Daimler recalled 4,115 Freightliners to fix improperly tightened brake caliper mounting bolts that could cause brakes to fail.
Daimler also recalled 1,545 Freightliner Customer Chassis Corp. MT45G and MT55G vehicles from the 2018-19 model years. Improper tightening of the engine ground stud could lead to overloading of electrical wires, melting and an increased risk of fire. Daimler said half of the recalled trucks could have the grounding issue.
The nation’s leading truck maker also recalled 11 compressed natural gas-powered Freightliner Business Class M2 and 114SD models built with a damaged O-ring installed within a pressure relief device. An unintended venting of a full tank of CNG in an enclosed area with an ignition source present could increase the risk of a fire. All 11 vehicles from the 2018-19 model year are at risk.
The NHTSA recall numbers are 18V702000 and 18V703000 (caliper bolts), 18V697000 (electrical ground) and 18V701 (CNG tank).
Daimler said it would inspect and replace affected parts in all four recalls at no charge.