NHTSA campaign 21V953000 · Mack campaign SC0433
Mack Recall 21V-953: Parking Brake May Release Unexpectedly
- Recall influenced by NHTSA's Office of Defects Investigation
NHTSA recall 21V953000 (Mack campaign SC0433) was reported by Mack Trucks, Inc. on December 9, 2021, with 20,668 vehicles potentially affected (per NHTSA). NHTSA's record lists the Mack TERRAPRO (MRU), Mack MRU, Mack TE and more for model years 2008–2022. Owners were notified on February 8, 2022, per NHTSA.
Updated daily from NHTSA's recall files
Is my vehicle included?
This page lists, by model year, the vehicles NHTSA's recall record names for campaign 21V953000 in the model years try.vin imports (1995 and later); NHTSA's own record can list more. A model year on the list doesn't mean every vehicle of that year is included, and some may already have been repaired.
To see whether a specific vehicle is included and still needs the repair, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Key facts
- NHTSA campaign
- 21V953000 (also written 21V-953 or 21V953)
- Filed by
- Mack Trucks, Inc.
- Mack campaign number
- SC0433
- Report received
- Potentially affected
- 20,668 vehicles (per NHTSA)
- Component
- Parking Brake
- Owners notified
Repair completion: 61.22% (latest rate the manufacturer reported to NHTSA; dataset updated October 21, 2026)
NHTSA cautions against comparing completion rates across recalls or manufacturers. How try.vin reads them.
Vehicles listed for this recall
NHTSA's recall record lists these vehicles for recall 21V953000. try.vin imports model years 1995 and later, so NHTSA's own list can be longer. Model years with a try.vin recall page link to it. Build dates are NHTSA's range for a model year (per NHTSA); a vehicle built in that range is not necessarily included.
NHTSA's recall notice
As NHTSA's recall record states it for campaign 21V953000.
Defect description
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.
Safety consequence
The unexpected release of the parking brake may allow the vehicle to rollaway, increasing the risk of a crash.
Manufacturer 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.
Sources
Official NHTSA notice for recall 21V953000
Campaign details come from NHTSA's recall files, which try.vin imports once a day. The plain-language subject and the completion rate come from the U.S. Department of Transportation's Recalls Data dataset. How try.vin reads recall data.