Steering:power assist:hydroboost unit
Defect Summary
Incorrect manufacture of the hydroboost cylinder allows the ball socket clamp to contact right side steering lever on an extreme left turn and cause flexing of the cylinder rod .
Safety Consequence
This flexing can cause seal failure or cylinder failureof the hydroboost unit and result in loss of steering control and result in avehicle accident.
Corrective Action
Replace incorrectly built boost cylinders.
Similar Recalls
Other recalls from Mack Trucks, Inc. or involving Steering.
FAQ: Recall 91V080000
Your rights, the repair process, and what each field on this page means.
What is recall 91V080000?
NHTSA recall 91V080000 was issued by Mack Trucks, Inc. on May 23, 1991. It addresses: Steering:power assist:hydroboost unit. The recall affects approximately 35 vehicles, with the defect involving the Steering component.
How do I get this recall repaired?
Contact any authorized Mack Trucks, Inc. dealer and reference NHTSA recall ID 91V080000 or the manufacturer campaign number NR (Not Reported). Under federal law, the repair is completely free regardless of vehicle age or owner history.
Is my vehicle included in this recall?
The only way to confirm is to look up your 17-character VIN at nhtsa.gov/recalls. NHTSA's tool will tell you if VIN-by-VIN this exact recall applies.
How long do I have to get a recall repair done?
There is no expiration on most federal safety recalls. Even if your vehicle is years old and you bought it used, the manufacturer is required to perform the repair at no cost.
Where does the data on this page come from?
All information on this page is sourced directly from the U.S. Department of Transportation public dataset for NHTSA recalls. Last refreshed: 2026-05-22. For the most current official notice, visit nhtsa.gov/recalls.