Vehicle recall 85V159000 · November 26, 1985

Mack MR600P and MS250P

The quick release valve support bracket mounted on the axle may crack.

Source: NHTSA data as of September 22, 2026. Last refreshed Sep 23, 2026, 2:43 AM UTC.

Summary: The quick release valve support bracket mounted on the axle may crack. This causes fatigue failure of the steel air lines leading to the rear parking brakes and chassis service brakes resulting in sudden loss of air pressure. Consequence of defect: this sudden loss of air to the brake chambers will result in automatic actuation of rear parking brake causing sudden rear wheel lockup which may contribute to an accident.
Remedy: Install a redesigned valve support bracket.
Notes: System: parking brakes air lines, quick release valve bracket.vehicle description: mid-liner trucks.

Recall details

NHTSA campaign: 85V159000
Reported to NHTSA: November 26, 1985
Filed by: MACK TRUCKS, INCORPORATED
Owner notification: November 26, 1986
Vehicles potentially affected: 3,308
Initiated by: the manufacturer
Components: Parking brake › Driveline › Hydraulic › Hoses, lines/piping, and fittings

Recall 85V159000 on nhtsa.gov, with the manufacturer’s documents

Vehicles covered

As listed by NHTSA. A recall usually covers only some vehicles of each model and year, often a production date range.

Mack MR600P (1984-1985): 1985, 1984
Mack MS250P (1984-1985): 1985, 1984

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