A fire risk from a Cummins Inc. (NYSE: CMI) fuel rail is leading 26 truck, bus and motorhome manufacturers to recall a total of nearly 45,000 vehicles.

In a recall filing May 12 with the National Highway Traffic Safety Administration (NHTSA), Cummins said the likelihood of a fire in affected L9 and ISX12 engines built between Jan. 2, 2017 and Oct.16, 2020 was about 1%. 

The issue is a sealing washer that may not seat correctly in the pilot bore holes, allowing an undetected and prolonged diesel fuel spray in the high-pressure fuel rail assembly. If an ignition source were present, a fire could occur. 

The rail end sealing bores in the fuel rail may have undersized pilot bores for the sealing washer. That could prevent the washer from properly seating, potentially resulting in inadequate load for the joint to remain properly sealed in service. Statistical process control for the pilot bores was confirmed after Oct.19, 2020, Cummins said..  

No accidents, fires or injuries

Cummins said it knows of no reports of accidents, fires or injuries related to the condition. 

The recall consists of engines installed in buses, emergency vehicles and recreational vehicles. The potential hazard is relatively hard to predict. A driver may see or smell diesel fuel. In some cases, the check engine lamp may illuminate. Passengers and riders could be more vulnerable and at greater risk of potential injury than in other applications

On. Feb. 10, a  field service technician reported to Cummins that eight buses belonging to one e customer had been repaired since December 2020 for leaks at sealing washers in the fuel rail. 

The next day, Cummins began a safety investigation, ultimately deciding in April to issue a technical service bulletin that authorized dealers to replace rails with washer leaks with a different rail and associated fuel lines. A week later, Cummins began a safety recall that will involve free inspections and repairs at customer repair facilities.

Daimler Trucks North America was the first vehicle maker to report the issue as a companion safety recall to the Cummins’ recall. The DTNA recall affects 9,662 vehicles — about 20% of the total  — across four model years of Freightliner, Western Star and Freightliner Custom Chassis Corp. nameplates.

Remedy in July

The specific remedy from Cummins won’t be ready until July. That means customers will get two letters. The first one on June 19 will acknowledge the potential problem. A second letter planned for July will instruct customers how to arrange inspections and possible repairs.

In addition to DTNA, the manufacturers impacted include the other three major commercial truck makers — Volvo Trucks North America, Navistar International and PACCAR Inc. (NASDAQ: PCAR) Others include school bus makers Blue Bird Corp., Gillig Corp., Tiffin Motorhomes and Pierce Manufacturing Inc.

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