- The problem
- PACCAR Incorporated (PACCAR) is recalling certain 2026-2027 Peterbilt 579 and 2027 Kenworth T680 tractors. The trailer air connection quick release (QR) valve in the air brake system may have been incorrectly installed, which can cause the trailer to become unstable after the driver applies the brakes. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 121, "Air Brake Systems."
- The risk
- An incorrectly installed quick release valve that does not function properly can increase the risk of a crash.
- The fix
- Paccar inspected and reinstalled the valves, as necessary, free of charge. All affected tractors have been repaired and therefore no owner notification letters are necessary. Owners may contact Peterbilt's customer service at 1-940-591-4220 and Kenworth's customer service at 1-425-828-5888. PACCAR's number for this recall is 26PACC.
Vehicle safety record
2026 Peterbilt 579 Problems, complaints & recalls
Owners have filed 1 complaint about the 2026 Peterbilt 579 with NHTSA, most often about the brakes (1). Those complaints describe 1 injury. It is covered by 2 recalls, the latest in July 2026 for the quick release valve. For comparison, the 2025 has 0 and the 2027 has 0.
NHTSA data checked
FFar more problems than a typical 579 year, for its age
#165 most complained-about 2026 vehicle
- Complaints
- 1
- Recalls
- 2
- Crashes
- 0
- Fires
- 0
- Injuries
- 1
- Deaths
- 0
Most common 2026 Peterbilt 579 problems
Share of all 1 complaints. One complaint can name more than one area. Tap an area for its complaints and recalls.
2026 Peterbilt 579 recalls 2
Recall repairs are free. Your dealer fixes them whether or not you bought the car there - check your VIN at nhtsa.gov/recalls to see if yours is done. What to do
- The problem
- PACCAR Incorporated (PACCAR) is recalling certain 2024-2026 Kenworth T480, T680, T880, W990, Peterbilt 520, 536, 537, 548, 567, 579, 589, 2025 Kenworth T180, Peterbilt 535, 2025-2026 Kenworth T280, T380 and L770 vehicles. The tail brake light, upper and lower beam headlights, reverse light, and turn signal may not illuminate as intended. In addition, the lift axles, if lowered, may revert to a raised position, or oscillate up and down when the signal warning lights are activated. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 108, "Lamps, Reflective Devices and Associated Equipment."
- The risk
- Delayed and unsteady headlights can result in insufficient illumination of the road, decreasing the driver's visibility and increasing the risk of a crash. In addition, an unexpected position change of the lift axles may increase the risk of injury.
- The fix
- Dealers will update the VCU software, free of charge. Owner letters were mailed August 19, 2025. Owners may contact Kenworth's customer service at 1-425-828-5888 and Peterbilt's customer service at 1-940-591-4220. PACCAR's number for this recall is 25PACF.
What owners say
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1 complaints about the 2026 Peterbilt 579
Newest first, as filed with NHTSA by owners.
The contact was the operator of a 2026 Peterbilt 579 for an employer. The contact stated that whether driving 30 MPH or 65 MPH, after another vehicle entered the lane in front of the vehicle, the Forward Collision Avoidance: AEB and Lane Keep Assist systems erroneously activated and brought the vehicle to an unsafe and abrupt stop. The contact stated that the RADAR system had experienced a False Positive alert of a possible crash, even though the vehicle was at a safe driving distance ahead. The contact stated that...
Read the full complaint
the failure caused other driver's behind the vehicle to run off the road or skid to a stop to avoid crashing into the rear of the vehicle. The contact stated that the failure also occurred with another vehicle approximately 100-feet ahead coming over into the lane, and the AEB activated, causing the wheels to lock up, bringing the vehicle to an abrupt stop. The contact stated that other drivers angrily honked at him. On one occasion, the contact was followed by an irate driver for ten minutes after the failure had occurred. The contact was concerned for his safety and the safety of the public because the system could not be overridden. The contact stated that on one occasion while his brother was driving the vehicle at a moderate speed, while the contact was asleep in the sleeping netting which the contact believes was not DOT approved, the AEB system activated and sent the contact's body forward, causing his rib cage to strike a cabinet inside the sleeper berth, causing an injury. The contact had not sought medical attention. The contact stated that the employer was notified of the failures with the vehicle, and the contact was informed to keep driving the vehicle as-is or seek other employment. The contact stated that the RADAR system also experienced False Positive alerts and inadvertent AEB activation while driving and approaching bridges or structures that cast shadows onto the roadway bringing the vehicle to an abrupt stop. The contact stated that prior to the abrupt stop, there was a picture of the hood on the instrument panel in RED, and instantly the vehicle came to a complete stop. The contact stated that the messages: "Auto-Electric Brakes - Disabled; Auto Lane - Defective; Lane Assist - Defective; and Lane Assist - Disabled" were displayed. The contact stated that after turning off and restarting the vehicle, all the messages were cleared from the system. The vehicle was not taken to be diagnosed or repaired. Neither the local dealer nor the manufacturer was notified of the failures. The approximate failure mileage was 200.
Peterbilt 579: every year compared
All 579 yearsQuestions about the 2026 Peterbilt 579
Does the 2026 Peterbilt 579 have any recalls?
Yes - NHTSA lists 2 recalls for the 2026 Peterbilt 579: quick release valve (July 2026); software (June 2025). Recall repairs are free at any authorized dealer. Enter your VIN at nhtsa.gov/recalls to see whether yours has been fixed.
What are the most common problems with the 2026 Peterbilt 579?
By the complaints owners filed with NHTSA, the most common problem areas are the brakes (1).
How many complaints has the 2026 Peterbilt 579 had?
1 complaints have been filed with NHTSA, the first on August 22, 2025 and the latest on August 22, 2025. Of these, 0 describe a crash and 0 a fire, and together they report 1 injury and 0 deaths.
Is the 2026 Peterbilt 579 a reliable vehicle?
Its Safety Index is 19 out of 100 (grade F: far more problems than a typical Peterbilt 579 year, for its age). The index weighs complaints, crashes, fires, injuries, deaths and recalls against how long the vehicle has been on the road, compared with the same model's other years. It is not a measure of every repair - read the complaints and owner experiences, and have any used vehicle inspected before you buy.
Which Peterbilt 579 years have the most complaints?
2022 (7), 2018 (6), 2023 (4). See every Peterbilt 579 year compared.
What should I do if my 2026 Peterbilt 579 has a problem?
If it is a safety problem, stop driving it if it is unsafe and contact your dealer. Report it to NHTSA at nhtsa.gov/report-a-safety-problem - enough reports start investigations and recalls - and share your experience here so other owners know what to look for.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) complaints and recalls, checked . Complaints are owners' own reports and are not verified. How we use the data