Recall 11V272 affects 1,524 2011-2012 Mack trucks for slack adjuster housings that can crack under braking. Repair is free at any franchised Mack dealer.
Mack is recalling 1,524 2011-2012 Pinnacle (Chu), Pinnacle (Cxu), Leu, Granite (Gu), Gu, and Mru trucks because Gunite automatic slack adjuster housings can crack during normal braking. A cracked slack adjuster can cause loss of braking and increase crash risk; Mack dealers will complete the recall repair free once available.
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What's wrong?
The automatic slack adjuster is part of the air-brake system on 2011-2012 Mack trucks, including Pinnacle (Chu), Pinnacle (Cxu), Leu, Granite (Gu), Gu, and Mru models. It keeps the brake linkage at the correct distance as the brake linings wear, so the brakes apply with the intended movement and force.
On affected trucks, the Gunite slack adjuster housing was not cast with enough structural strength. The iron did not fully join during casting, leaving the housing weaker than intended. Under normal operating loads, the housing can break at the handle. Once that happens, the adjuster can no longer keep the brake linkage in the proper position.
There is no warning sign before failure. The filing does not describe a dashboard light, noise, pedal change, or other owner-visible symptom before the slack adjuster housing breaks.
Who's affected?
Covers 6 Mack truck models across the 2011 and 2012 model years, all tied to the same automatic slack adjuster brake component.
| 2012 Mack Pinnacle (Chu) | brake system |
|---|---|
| 2011 Mack Pinnacle (Cxu) | brake system |
| 2012 Mack Leu | brake system |
| 2012 Mack Granite (Gu) | brake system |
| 2011 Mack Pinnacle (Chu) | brake system |
| 2012 Mack Pinnacle (Cxu) | brake system |
| 2011 Mack Leu | brake system |
| 2011 Mack Gu | brake system |
| 2011 Mack Mru | brake system |
| 2012 Mack Mru | brake system |
| Units affected | 1,524 |
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?
Under normal braking, the affected slack adjusters can crack and cause loss of braking, increasing crash risk. If braking feels abnormal, stop using the truck and call a Mack dealer for instructions before moving it again. Repair will be free at any franchised Mack dealer once available.
What should I do?
- Check your VIN to confirm your 2011-2012 Mack Pinnacle (Chu), Pinnacle (Cxu), Leu, Granite (Gu), Gu, or Mru truck is included in this recall.
- Contact your nearest franchised Mack dealer to confirm the slack-adjuster replacement status before scheduling service.
- Bring the recall notice if Mack mailed one. If not, reference recall number 11V272 when you call.
- Schedule the free slack-adjuster replacement that fixes the brake adjusters at risk of cracking under normal braking loads.
- Drive cautiously until the repair is complete. Leave extra following distance and avoid hard braking when possible.
What happens at the repair
The repair record calls for Mack dealers to replace the Gunite automatic slack adjusters covered by this recall at no charge once the remedy is available for the VIN. At the dealer, a Mack technician removes the subject slack adjusters from the brake system and installs replacement adjusters so the housing is no longer the recalled casting. The filing says the recall repair began on August 24, 2011. Ask the Mack service desk to confirm parts availability for your VIN and complete the free recall repair.
Timeline
| May 3, 2011 | NHTSA published the recall |
|---|---|
| August 12, 2011 | Owner notification mailed |
Frequently asked questions
What is recall 11V272?
Recall 11V272 covers 1,524 2011-2012 Mack trucks equipped with Gunite automatic slack adjusters. The slack adjuster housing can crack under normal braking, causing loss of braking and increasing crash risk. Mack dealers replace the subject slack adjusters for free.
What should I do if my 2011-2012 Mack Pinnacle (Chu), Pinnacle (Cxu), Leu, Granite (Gu), Gu, or Mru is on this recall?
Check your VIN to confirm your specific truck is included in recall 11V272. If it is, contact a franchised Mack dealer to schedule the slack-adjuster replacement. Reference recall number 11V272 when you call. The repair is free.
Does the Mack recall repair cost anything?
No. Federal recall law requires manufacturers to repair safety recalls at no cost, and Mack dealers replace the subject Gunite automatic slack adjusters free of charge. Have recall 11V272 ready when you call the dealer or Mack at 1-800-528-6586.
What is the safety risk in recall 11V272?
The safety risk is loss of braking. Mack says the slack adjuster housing can crack under normal braking loads, which can cause loss of braking and result in a vehicle crash. Check your VIN, then arrange the free dealer repair if your truck is included.
What if I bought the Mack truck used?
The free recall repair still applies. Federal recall law follows the vehicle, not the first owner. Check your VIN to confirm whether your specific 2011-2012 Mack truck is included, then contact a franchised Mack dealer and reference recall 11V272.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/11V272000 |
|---|---|
| Mack customer service | 1-800-528-6586 |
| NHTSA recall # | 11V272 |
| NHTSA recall # (full) | 11V272000 |
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 →