2020–2021 Peterbilt 520 Recall: Quick release valve on the rear brake signal hose may be missing

NHTSA campaign 21V720000 · Service Brakes, Air · filed Sep 16, 2021 · verified Jul 30, 2026

Units reported

Manufacturer

PACCAR Incorporated

Risk

Crash / injury

Owner letters

Mailing began Oct 7, 2021

The defect

PACCAR Incorporated (PACCAR) is recalling certain 2020-2021 Peterbilt 520 vehicles. The quick release valve on the rear brake signal hose may be missing. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 121, "Air Brake Systems."

The risk

A missing quick release valve cannot ensure correct rear brake release timing, increasing the risk of a crash or injury.

Check whether your specific vehicle is affected

Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.

Check VIN on NHTSA →

The fix — what to do

Dealers will inspect the vehicles for a missing quick release valve, and install one if necessary, free of charge. Owner notification letters were mailed on October 7, 2021. Owners may contact PACCAR's customer service at 1-940-591-4220 (Peterbilt). PACCAR's number for this recall is 21PBK.

Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.nhtsa.gov.

Affected vehicles

Make	Model	Model years
Peterbilt	520	2020, 2021

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Source: NHTSA recall database, campaign 21V720000 (manufacturer number 21PBK). Data last verified Jul 30, 2026.