2026 Peterbilt 579 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2026 Peterbilt 579, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Brakes1100.0%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
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 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
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .