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Service bulletin 23KWJ

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 id10248329
Published by NHTSA2024-01-05
Manufacturer's number23KWJ
Manufacturer's date2023-12-27
NHTSA componentSERVICE BRAKES, AIR

NHTSA's summary

Safety Recall 23KWJ: T280/T380/T480 Delayed Trailer Brake Release T280/T380/T480 Delayed Trailer Brake Release. Safety Recall Certain T280/T380/T480 chassis built with 2.1m Medium Duty End of Frame Trailer Connections and Tractor Protection Valves may not meet the standard trailer brake release timing requirements by 0.5 seconds. A delay in the trailer brake release may create momentary instability to the trailer and increase the risk of a crash.

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

Brakes

Vehicles listed
KENWORTH T2802021
KENWORTH T2802022, 2023, 2024
KENWORTH T3802020 to 2021
KENWORTH T3802022, 2023, 2024
KENWORTH T4802020 to 2021
KENWORTH T4802022, 2023, 2024

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

Recalls for the same vehicles and component
20247442024-12-09. Brakes
24V9150002024-12-09. ELECTRICAL SYSTEM:SOFTWARE; SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:CONTROL UNIT/MODULE
24V1450002024-02-23. SERVICE BRAKES, AIR:SUPPLY:RESERVOIR/TANK
23V6610002023-09-29. SERVICE BRAKES, AIR
20235242023-09-21. Brakes
20230702023-02-15. Brakes
23V0870002023-02-15. SERVICE BRAKES, AIR
22V4240002022-06-15. SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:ABS WARNING LIGHT

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
24KWE/24PBE2026-01-06. Emissions. The parts section has been updated for clarity. The right-hand shift stalk may have an improper wire harness terminal crimp within the wire harness connector. Loss of communication between the right-hand shift stalk and the vehicle may result in the vehicle being disabled after it comes to a stop, thereby increasing the risk of crash or injury. A warning will appear on the dash display when communication is lost, including transmission or engine warnings, “!” next to DNR/DNRP indicator, “-“ in the DNR/DNRP indicator, and/or chimes, depending upon whether you are operating a diesel/gas or battery electric vehicle.
24KWD2025-11-05. Service bulletin. SAFETY RECALL Additional chassis have been included. The chassis list has been updated. Certain T370 / T440 / T470 / T480 / T660 / T680 / T800 / T880 / W900 / C500 chassis may be equipped with air tank reservoirs that have less than twelve times the combined volume of all service brake chambers which fail to conform to Federal Motor Vehicle Safety Standard (FMVSS) No.121, Air Brake Systems.
23KWJ2023-11-10. Service bulletin. Safety Recall Interim Notification Certain T280/T380/T480 chassis built with 2.1m Medium Duty End of Frame Trailer Connections may not meet the standard trailer brake release timing requirements by 0.5 seconds. A delay in the trailer brake release can create instability to the trailer and increase the risk of a crash. Parts and repair procedures are not yet available. This bulletin will be updated when a repair path is determined.
23KWB2023-06-03. Service bulletin. Parts and repair procedures are now available. Kenworth has determined that a safety defect exists in certain Model Year 2021-2024 T280, T380, and T480 chassis with air brakes. The brake pedal plunger which connects the brake pedal to the brake valve may dislodge after the pedal is fully depressed, and rapidly released (side slip foot brake release). If the plunger in the brake pedal assembly dislodges, the driver may be unable to apply the service brakes, which may increase the risk of a crash.
S0172022-07-01. Service bulletin. Due to a global chip shortage, certain chassis will be shipped without the Bendix side object detection radar modules and A-pillar displays. Refer to Sales Bulletin TE2680 for details.