Recall 12V037 covers 2 2012-2013 Mack Granite (Gu) trucks for Bendix relay-valve leakage that applies brakes. Temporary repair is free at any franchised Mack dealer.
Mack is recalling 2 2012-2013 Granite (Gu) trucks under recall 12V037 because Bendix ATR-6 traction relay valves can leak internally in extremely cold conditions. That leakage can apply the brakes continuously, overheat the brakes, start a fire, or lock the wheels and cause loss of vehicle control; the Mack dealer repair will be free once available.
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What's wrong?
The Bendix ATR-6 traction relay valve in affected 2012-2013 Mack Granite (Gu) trucks is part of the air-brake control system. In normal operation, the valve routes compressed air to the primary or secondary brake circuit only when the system calls for brake application. That air pressure is what moves the brake hardware and applies the brakes on a heavy truck.
In severe cold, the relay valve can develop an internal air leak. Instead of holding air back until braking is requested, the valve lets pressure pass into an affected brake circuit. That pressure keeps the brakes applied, creating continuous brake application even when the driver is not pressing the brake pedal. The defect is tied to trucks equipped with Bendix ATR-6 traction relay valves.
There is no warning sign before failure. If the leak develops in cold conditions, the first thing an owner or driver notices is the brake drag or continuous brake application itself.
Who's affected?
Covers the 2012 and 2013 model years for the same brake system check valve.
| 2013 Mack Granite (Gu) | brake system |
|---|---|
| 2012 Mack Granite (Gu) | brake system |
| Units affected | 2 |
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?
Unintended brake application can overheat the brakes and lead to a fire. It can also lock the wheels, cause loss of vehicle control, and increase the risk of a crash. If the brakes drag, overheat, or feel abnormal, stop when safe and call a Mack dealer. Repair will be free at any franchised Mack dealer once available.
What should I do?
- Check your VIN to confirm your 2012-2013 Mack Granite (Gu) is included in this recall.
- Review Mack's owner notice for temporary free repair instructions before scheduling service.
- Contact a franchised Mack dealer to ask for the temporary repair for the Bendix ATR-6 relay valve brake-pressure leak.
- Reference recall number 12V037 when you call, and ask whether the permanent Bendix remedy is open for your VIN.
- Drive cautiously until service is complete. Stop in a safe place if the brakes drag, overheat, or apply without warning.
What happens at the repair
At the dealer, a Mack technician performs the temporary repair Mack identified for the Bendix ATR-6 traction relay valve issue. The temporary service is free of charge. The permanent Bendix remedy is not listed as available yet, so the final dealer repair cannot be treated as ready to schedule from this remedy text. Once Bendix develops the permanent fix and Mack opens the final repair, the dealer repair will be free. Ask the Mack service desk what temporary work is available for your VIN and whether the truck needs any handling limits before the final remedy opens.
Timeline
| February 1, 2012 | NHTSA published the recall |
|---|---|
| April 23, 2012 | Owner notification mailed |
Frequently asked questions
What is recall 12V037?
Recall 12V037 covers 2 2012-2013 Mack Granite (Gu) trucks equipped with Bendix ATR-6 traction relay valves. In extremely cold conditions, the valve can leak internally and send air pressure to the brakes, causing continuous brake application. Mack provides the recall service free of charge.
What should I do if my 2012-2013 Mack Granite (Gu) is on this recall?
Check your VIN to confirm your specific truck is included in recall 12V037. If it is, contact a franchised Mack dealer and reference recall number 12V037. Mack also lists owner support at 1-800-866-1177. The recall service is free.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and Mack's remedy states that the service will be performed free of charge. Ask the Mack dealer which recall remedy applies to your truck before scheduling service.
What is the safety risk?
The safety risk is unintended brake application. The brakes can overheat and lead to a fire, or the wheels can lock up and cause the driver to lose control of the vehicle. Mack's free recall service addresses the brake valve problem.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/12V037000 |
|---|---|
| Mack customer service | 1-800-866-1177 |
| NHTSA recall # | 12V037 |
| NHTSA recall # (full) | 12V037000 |
Source documents
-
Download Recall Investigation Document (PDF) (PDF) - Download Recall Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Defect / Noncompliance Notice (PDF) (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on June 2, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →