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Service bulletin 21KWC

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10198759
Published by NHTSA2021-07-06
Manufacturer's number21KWC
Manufacturer's date2021-06-22
NHTSA componentFUEL SYSTEM, GASOLINE

NHTSA's summary

Safety Recall – Cummins Fuel Rail Leak – NHTSA ID: 21V391 / TC: 2021-323, Cummins Recall: C2423. Cummins PX9 and ISX12 fuel rails may leak around a sealing washer, potentially resulting in fuel leaks. Undetected prolonged diesel fuel spray in the presence of an ignition source may increase the risk of fire.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Fuel system

Vehicles listed
KENWORTH T1702017 to 2020
KENWORTH T2702017 to 2021
KENWORTH T3702017 to 2021
KENWORTH T4402017 to 2021
KENWORTH T4702017 to 2021
KENWORTH T8002017 to 2020
KENWORTH T800B2021
KENWORTH T8802017, 2018, 2019, 2020, 2021

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20213232021-05-26. Fuel System
21V3910002021-05-26. FUEL SYSTEM, DIESEL:FUEL INJECTION SYSTEM:FUEL RAIL
20185272018-09-25. Fuel System
20173612017-07-20. Fuel System
17V4430002017-07-13. FUEL SYSTEM, DIESEL
20170932017-02-20. Fuel System
17V1030002017-02-15. FUEL SYSTEM, OTHER:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
CE0372026-05-06. Warranty extension. KW & PB DEF Quality Sensor part number Q21-6127-001 for Cummins X15 engines has been added to this warranty policy.
CE0362026-05-06. Warranty extension. KW & PB DEF Quality Sensor part number Q21-6127-001 for PACCAR PX-7 and Cummins X15 engines has been added to this warranty policy.
43-0762026-01-06. Service bulletin. Certain vehicle model years 2020-2025 K270, K370, T270, T280, T370, T380, T480, T680, T880, W900 chassis have updated Greenhouse Gas (GHG) labels available for installation.
E3062023-11-10. Service bulletin. PACCAR MX-11 & MX-13 EPA2021 Fuel Filter Drain & Change Info Incorrect fuel filter drain and replacement procedures on EPA21 MX-11 and MX-13 engines can result in the following Debris and contaminants introduced into the high-pressure fuel system. Denial of warranty claims for injector and/or fuel system faults. Misfire, rough running, engine knock, and other associated faults and symptoms. Correct fuel filter procedures are outlined in attached service documentation.
E2902023-07-05. Service bulletin. FIX-AS-FAIL Updated procedures and claim filing information. EPA2021 injector cleaning is referenced in RMI for certain injector faults. Complete the procedures in E290. Refer to E300 for in-tank additive information
03-087 (E295)2023-03-06. Service bulletin. Certain Model Year 2021-2024 chassis with PACCAR MX engines and optional fuel filter restriction virtual gauge may display incorrect restriction levels. The virtual gauge will be temporarily disabled until a revised sensor strategy is developed.
43-0712021-10-05. Service bulletin. Fix-As-Fail – Due to undersupply issues, only a limited supply of Diesel Exhaust Fluid (DEF) sensors are available. As a temporary solution, after PACCAR confirms a DEF sensor is not available, a temporary software update will allow a vehicle to continue operation with a failed DEF sensor by disabling the DEF sensor diagnostics.
44-0332020-08-05. Service bulletin. Non-Safety Campaign – The end cap welds on certain fuel tanks may not meet internal quality standards due to improper weld equipment settings. The fuel tanks will be replaced.
44-0302019-09-05. Service bulletin. Fix-As-Fail - Nylon fuel lines may be too short, potentially resulting in a cracked or loose, low pressure fuel fitting at the engine or fuel tank, which may introduce air into the fuel system resulting in a hard-to-start or no-start condition.
44-0292018-05-07. Service bulletin. Non-Safety Campaign - The coolant lines connected to the fuel filter may interfere with the brake chamber on certain T680/T880 vehicles. Repeated interference may cause the fittings to break and leak coolant.