Recall 21V720 affects 15 2020-2021 Peterbilt 520 vehicles for a missing rear brake quick release valve. Repair is free at any franchised Peterbilt dealer.
Peterbilt is recalling 15 2020-2021 520 vehicles because the rear brake signal hose is missing a quick release valve. A missing valve cannot ensure correct rear brake release timing, increasing the risk of a crash or injury, and Peterbilt dealers will complete the recall repair free of charge.
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What's wrong?
The rear brake signal hose on a 2020-2021 Peterbilt 520 is part of the air-brake control system. It carries the air signal from the brake controls toward the rear brake circuits, so the rear brakes apply and release at the timing the system was designed to meet. A Bendix QR-1 quick release valve, part number 08-01279, is supposed to help that air pressure exhaust close to the rear brakes instead of traveling farther through the plumbing.
On the recalled trucks, that quick release valve was left out. Without it, certain combinations of wheelbase, axle setup, brake type, and brake chamber size fail the brake timing requirements for FMVSS 121, Air Brake Systems. The issue is not a worn brake pad or an adjustment problem. It is a missing valve in the air-brake signal path.
There is no warning sign before failure. A driver should not expect a dashboard message, noise, or pedal change that confirms the valve is missing.
Who's affected?
Both model years are tied to the same brake system issue.
| 2020 Peterbilt 520 | brake system |
|---|---|
| 2021 Peterbilt 520 | brake system |
| Units affected | 15 |
| Field incidents | NHTSA has logged no field incidents to date. |
The year and model narrow the scope, but the VIN decides. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
A missing quick release valve can affect rear brake release timing, increasing the risk of a crash or injury. If braking feels abnormal, pull over safely and call a Peterbilt dealer before continuing. Schedule the inspection soon even if the brakes feel normal. Repair is free at any franchised Peterbilt dealer.
What should I do?
- Check your VIN to confirm your 2020-2021 Peterbilt 520 is included in this recall.
- Contact a franchised Peterbilt dealer to schedule the free quick-release-valve inspection and installation that corrects rear brake release timing.
- Bring the recall notice if you have it, and reference recall number 21V720 when you call.
- Drive cautiously until the repair is complete; leave extra following distance and avoid hard braking.
What happens at the repair
At the dealer, a Peterbilt technician inspects the rear brake signal hose for the missing quick release valve. If the valve is missing, the technician installs it at no charge. Parts and labor are free under the recall. If you paid to fix this problem before receiving the owner notice, PACCAR's general reimbursement plan lets you seek repayment for documented costs. Bring repair invoices or other proof of payment to the service desk.
| Reimbursement | Reimbursement available |
|---|
Timeline
| September 16, 2021 | NHTSA published the recall |
|---|---|
| October 7, 2021 | Owner notification mailed |
| November 15, 2021 | Dealer notification began |
| November 15, 2021 | Dealer notification ended |
| November 15, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V720?
Recall 21V720 covers 15 2020-2021 Peterbilt 520 vehicles built without the quick release valve on the rear brake signal hose. Without that valve, rear brake release timing is not assured, which increases crash or injury risk. Peterbilt dealers inspect and install the valve for free.
What should I do if my 2020-2021 Peterbilt 520 is on this recall?
Check your VIN to confirm your specific truck is included in recall 21V720. If it is, contact a franchised Peterbilt dealer and ask for the 21PBK inspection. The dealer will inspect the rear brake signal hose and install the missing quick release valve for free if needed.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to correct the safety defect at no cost to the owner. For recall 21V720, Peterbilt dealers inspect the vehicle and install the rear brake quick release valve free of charge if the inspection finds it is missing.
What is the safety risk?
The risk is incorrect rear brake release timing. A missing quick release valve on the rear brake signal hose means the air brake system does not meet Federal Motor Vehicle Safety Standard 121, and the official consequence is increased crash or injury risk.
When were owners notified about recall 21V720?
Peterbilt owner notification letters were mailed on October 7, 2021. If you bought the truck after that date or never received the letter, check your VIN and give the dealer recall number 21V720 or Peterbilt recall number 21PBK when scheduling service.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V720000 |
|---|---|
| Peterbilt customer service | 1-940-591-4220 |
| NHTSA recall # | 21V720 |
| NHTSA recall # (full) | 21V720000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →