General Motors is recalling 40,428 medium-duty trucks that Navistar Inc. built for the automaker because brake fluid leaking into a pressure sensor assembly can cause a fire.
GM reported 11 instances of fire, smoke or flame in the 2019 to 2023 Chevrolet Silverado 4500HD, 5500HD and 6500HD Class 4-6 trucks between July 2021 and January this year. The National Highway Traffic Safety Administration reported no accidents or injuries.
GM issued a “do not drive” notice to owners because a fire can start even when the engine is turned off.
The issue affects about 1% of the recalled GM vehicles. Navistar did not respond to emailed requests about the inclusion of International-branded products in the recall. But it submitted a similar recall notice to NHTSA on April 20 covering 9,170 International CVs. All of those trucks are suspected to have the issue, prompting a “do not drive” notice.
Navistar is a contract manufacturer for GM
Navistar is the contract manufacturer of GM’s medium-duty trucks. Separately, it also builds chassis for GM’s medium-duty cargo and passenger vans.
GM opened a product investigation in August following a claim of a vehicle fire on a 2019 Silverado medium-duty truck. It coordinated with Navistar to review field data and warranty returns of brake pressure sensors.
GM and Navistar could not duplicate the condition of the original complaint. But a later warranty return of a sensor showed heat damage. Further analysis showed that brake fluid was present past the diaphragm seal, into the brake pressure switch and through the actual wire harness into the pump’s fuse.
A corrosion-inhibiting zinc-nickel plating and sealant also showed signs of delamination, which allowed slow seepage of brake fluid past the diaphragm seal.
GM dealers will replace the master cylinder pressure sensor free of charge. Dealers also will inspect the associated wire harness and replace it if necessary. As of March 23, the replacement pressure sensor assemblies in production do not use the faulty corrosion inhibitor sealant.
Dealers were notified of the recall on April 13. Customer letters will be mailed May 29. The NHTSA recall number is 23V-266.
Editor’s note: Updates with Navistar recall.
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