Recall 15V275 covers 2,124 2011-2016 Mack LR6, Leu, and Mru trucks for a crankcase vent elbow detachment risk. Repair is free through Cummins service centers.
Mack is recalling 2,124 2011-2016 LR6, Leu, and Mru trucks under recall 15V275 because excessive engine crankcase pressure can detach the 90-degree elbow from the crankcase ventilation breather. That failure can let engine oil reach hot surfaces and raise fire risk, and the Mack dealer repair will be free once Mack opens it.
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What's wrong?
The crankcase ventilation breather on 2011-2016 Mack LR6, Leu, and Mru trucks helps manage pressure inside the engine. As the engine runs, combustion gases and oil vapor build inside the crankcase. The vent tube assembly routes that pressure and vapor away from the engine so the crankcase does not stay over-pressurized.
On affected trucks with the Cummins Westport ISL Gas engine, excessive crankcase pressure can push the 90-degree elbow of the vent tube assembly off the breather exit tube. Cummins traced the pressure condition in known incidents mainly to a cracked piston. When the elbow detaches, engine oil can escape the intended ventilation path and reach hot engine surfaces.
Owners can see engine power drop, amber or red engine diagnostic lamps on the instrument cluster, or erratic engine operation. Those are warning signs that high crankcase pressure is present and the ventilation connection needs dealer attention.
Who's affected?
Spans LR6, Leu, and Mru trucks across the 2011-2016 model years, all tied to the engine component.
| 2016 Mack LR6 | Engine |
|---|---|
| 2011 Mack Leu | Engine |
| 2013 Mack Leu | Engine |
| 2015 Mack LR6 | Engine |
| 2012 Mack Leu | Engine |
| 2011 Mack Mru | Engine |
| 2012 Mack Mru | Engine |
| 2013 Mack Mru | Engine |
| 2014 Mack Leu | Engine |
| 2014 Mack Mru | Engine |
| 2015 Mack Leu | Engine |
| 2015 Mack Mru | Engine |
| 2016 Mack Leu | Engine |
| 2016 Mack Mru | Engine |
| Units affected | 2,124 |
| Field incidents | NHTSA has logged no field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
If engine oil reaches a hot surface, fire risk increases. Loss of engine power, amber or red engine diagnostic lamps, or erratic engine operation are warning signs tied to high crankcase pressure. Pull over safely and contact a Mack dealer if they appear. Repair will be free at any franchised Mack dealer once available.
What should I do?
- Check your VIN to confirm your 2011-2016 Mack LR6, Leu, or Mru is included in this recall.
- Use the Mack owner letter mailed June 12, 2015, if you received one; if not, call Mack customer service for current repair instructions.
- Reference recall number 15V275 and Mack recall SC0391 when you call Mack or the service location.
- Ask about the free vent-tube elbow securing work and ECM software update that limits crankcase pressure and helps keep engine oil off hot surfaces.
- Avoid operating the truck until Mack or the service location confirms the repair path for your VIN.
What happens at the repair
Once the final repair is available, a Mack technician at the service center secures the ends of the 90-degree elbow and reprograms the electronic control module. The software update is meant to adjust engine output during misfire conditions and limit crankcase pressure. Parts and labor are covered under the recall. Mack has a general reimbursement plan on file, so if you already paid for this repair, ask Mack Customer Service how to submit documentation for review under that plan.
| Reimbursement | Reimbursement available |
|---|
Timeline
| May 11, 2015 | NHTSA published the recall |
|---|---|
| June 12, 2015 | Owner notification mailed |
Frequently asked questions
What is recall 15V275?
Recall 15V275 covers 2,124 2011-2016 Mack LR6, Leu, and Mru trucks with crankcase pressure that can detach a 90-degree vent-tube elbow. If engine oil reaches a hot surface, fire risk increases. Cummins service centers handle the free repair for Mack.
What should I do if my 2011-2016 Mack LR6, Leu, or Mru is on this recall?
Check your VIN to confirm your specific truck is included in recall 15V275. If it is, contact a Mack dealer or Cummins service center and reference Mack recall number SC0391. The repair secures the vent-tube elbow and updates the ECM software for 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 Cummins service centers perform these repairs free of charge. The repair includes securing the 90-degree elbow ends and reprogramming the ECM software.
What is the safety risk?
The safety risk is fire. Excessive engine crankcase pressure can detach the 90-degree elbow from the crankcase ventilation breather. That can allow engine oil to reach hot surfaces, which increases the risk of a fire.
When were owners notified about recall 15V275?
The recall began on June 12, 2015. Because that date has passed, owners with an included VIN should contact a Mack dealer or Cummins service center now rather than wait for another letter. Reference Mack recall number SC0391 when you call.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/15V275000 |
|---|---|
| Mack customer service | 1-800-528-6586 |
| NHTSA recall # | 15V275 |
| NHTSA recall # (full) | 15V275000 |
Source documents
-
Download Owner Notification Letter (PDF) - Download Owner Notice (PDF)
- Download Recall Report (PDF)
- Download Quarterly Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on June 1, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →