Hearth Record

Steering: hydraulic power assist system (Mack)

Vehicle recall 91V-080. NHTSA received MACK TRUCKS, INCORPORATED’s report on May 23, 1991.

NHTSA’s own record, on nhtsa.gov

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The short answer

NHTSA received MACK TRUCKS, INCORPORATED’s report on May 23, 1991. Copied from NHTSA on Oct 28, 2026.

Every line below is in NHTSA’s own words, with its source beside it.

What’s wrong with it?

THIS FLEXING CAN CAUSE SEAL FAILURE OR CYLINDER FAILUREOF THE HYDROBOOST UNIT AND RESULT IN LOSS OF STEERING CONTROL AND RESULT IN AVEHICLE ACCIDENT.

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 .

Source:

NHTSA, Recalls flat file before 2010. Released Oct 28, 2026. Updated daily.

  • NHTSA’s part: Steering: hydraulic power assist system.

What should you do?

REPLACE INCORRECTLY BUILT BOOST CYLINDERS.

Source:

NHTSA, Recalls flat file before 2010. Released Oct 28, 2026. Updated daily.

  • How to reach the firm: SYSTEM: STEERING POWER ASSIST, HYDROBOOST ASSEMBLY.VEHICLE DESCRIPTION: CF AERIALSCOPE MODEL.
  • Check a vehicle by its VIN at NHTSA: the recalls still open on it are listed there.

Which ones are recalled?

NHTSA counts 35 vehicles potentially involved, across everything this recall names.

Source:

NHTSA, Recalls flat file before 2010. Released Oct 28, 2026. Updated daily.

  • Mack CFand 1988 and 1989, before the model years listed here

Who is recalling it?

  • Made by MACK TRUCKS, INCORPORATED.
Source:

NHTSA, Recalls flat file before 2010. Released Oct 28, 2026. Updated daily.

What the record doesn’t say

  • NHTSA’s recall file doesn’t say whether anyone was hurt.
  • Whether one vehicle or seat has been fixed: only its maker, or NHTSA’s lookup with a VIN, can say.
  • This recall names only model years before 2015, which have no pages here. Your VIN, at NHTSA, says which recalls are open on a vehicle.
  • How many have been returned or fixed isn’t in the notice.
Source:

Hearth Record wrote these lines.

Sources

Source:

Vehicle, car seat, tire and vehicle equipment recalls, owner complaints and crash ratings are from the National Highway Traffic Safety Administration (NHTSA). Copied on Oct 28, 2026.

How to read a record

Four things every record does, shown on an example record made up for this guide.

An example record, made up for this guide

An example nursing home

Made up for this guide: no real place is shown

Not fully inspected in over two years (CMS flag)

11 health citations at the latest inspection cycle

The state average is 14.3.

Source:

CMS, State and US Averages and Health Deficiencies. Released Oct 28, 2026. Updated monthly.

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Every fact names its source.

Who published it, when, and how often it changes sit beside each fact, with a link to the agency’s own file.

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