Service bulletins for the 2021 Peterbilt 520
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.
57 on file from NHTSA, as of 2026-10-19.
By type
By component
Only bulletins with component: Brakes are shown. Show all
| 13-060 | 2022-09-06. Service bulletin. SERVICE BRAKES. The service information for Bendix Air Dryer maintenance is being updated to include new procedures. |
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| 21 PBK | 2021-10-05. Service bulletin. SERVICE BRAKES, AIR. Safety Recall – Certain Model 520 trucks may have been built without a quick release (QR) valve. The absence of this valve could affect rear brake timing on certain vehicles equipped with a tri-drive or liftable tag axle and Dual Seated or Right Hand Stand-Up steering configurations. Vehicles will be inspected and, if necessary, a QR valve will be installed. |
| 13-055 | 2020-11-05. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; SERVICE BRAKES, AIR. Fix as Fail: Peterbilt has introduced an improved mounting bracket for low mount air tanks for vehicles built between January 01, 2017 and July 06, 2020. Torsional vibration may stress the currently-installed brackets and cause them to fail near the bottom of the frame rail. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.