# NHTSA recall 21V953000

A recall listed here may apply to a vehicle of this year, make and model. Only the manufacturer can say whether it applies to one vehicle: check the VIN with the official lookups.

- Published by: NHTSA \(United States\)
- Campaign number: 21V953000
- Manufacturer's number: SC0433
- Manufacturer: Mack Trucks, Inc.
- Reported: 2021\-12\-09
- Owners notified: 2022\-02\-08
- Component: PARKING BRAKE
- Units potentially affected: 20668
- Part numbers: 25117989

## What is wrong

Mack Trucks, Inc. \(Mack\) is recalling certain 2008\-2019 TerraPro \(MRU\) and 2019\-2022 TerraPro \(TE\) vehicles.  A brake control valve air leak into the attached exhaust hose can create excessive back pressure, causing the parking brake to release unexpectedly.


## What can happen

The unexpected release of the parking brake may allow the vehicle to rollaway, increasing the risk of a crash.


## The remedy

Dealers will remove the exhaust tube and fitting from the valve, free of charge.  Owner notification letters were mailed February 8, 2022. Owners may contact Mack customer service at 1\-800\-866\-1177.  Mack's number for this recall is SC0433.


## Notes

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.


## Remedy progress the manufacturer reported

- Report: Annual report 2, for 2025 quarter 1 to 2025 quarter 4
- Filed with NHTSA: 2026\-01\-05
- Vehicles in the campaign: 20668
- Reported remedied: 12652 \(61%\)
- Reported unreachable: 0
- Reported removed: 0

These are the manufacturer's totals for the whole campaign at the end of 2025 quarter 4, as filed with NHTSA. They do not say whether one vehicle has been remedied: check the VIN with the official lookups. The reports are from data as of 2026\-10\-19.

## Vehicles this campaign lists

- 2008 MACK MRU
- 2009 MACK MRU
- 2010 MACK MRU
- 2019 MACK TE
- 2020 MACK TE
- 2021 MACK TE
- 2011 MACK TERRAPRO \(MRU\)
- 2012 MACK TERRAPRO \(MRU\)
- 2013 MACK TERRAPRO \(MRU\)
- 2014 MACK TERRAPRO \(MRU\)
- 2015 MACK TERRAPRO \(MRU\)
- 2016 MACK TERRAPRO \(MRU\)
- [2017 MACK TERRAPRO \(MRU\)](/makes/mack/terrapro/2017/recalls.md). Listed as a series or trim of this model.
- [2018 MACK TERRAPRO \(MRU\)](/makes/mack/terrapro/2018/recalls.md). Listed as a series or trim of this model.
- [2019 MACK TERRAPRO \(MRU\)](/makes/mack/terrapro/2019/recalls.md). Listed as a series or trim of this model.
- [2022 MACK TERRAPRO \(TE\)](/makes/mack/terrapro/2022/recalls.md). Listed as a series or trim of this model.

## Investigated as PE20003

This recall followed 1 NHTSA investigation. An investigation is NHTSA looking into a possible defect. It is not a finding that a defect exists, and it does not say that any one vehicle is affected.

- PE20003: Preliminary evaluation, opened 2020\-04\-01, closed 2024\-01\-10. Vehicle Roll Away. PARKING BRAKE; PARKING BRAKE:CONVENTIONAL:AIR; SERVICE BRAKES, AIR:CONTROLS; SERVICE BRAKES, AIR:SUPPLY:HOSES, LINES/PIPING, AND FITTINGS.

From NHTSA's investigation file, as of 2026-10-19. JSON: [/v1/recalls/nhtsa/21V953000/investigations](/v1/recalls/nhtsa/21V953000/investigations)

## Check a VIN

- [NHTSA recall lookup by VIN, United States](https://www.nhtsa.gov/recalls)
- [Transport Canada recall search, Canada](https://wwwapps.tc.gc.ca/Saf-Sec-Sur/7/VRDB-BDRV/search-recherche/menu.aspx?lang=eng)

JSON: [/v1/recalls/nhtsa/21V953000](/v1/recalls/nhtsa/21V953000)

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