MACK MC SERIES 1979: PARKING BRAKE:DRIVELINE:AIR

General Information

NHTSA Campaign ID Number: 80V052000

Make Model Year
MACK MC SERIES 1979
Date Owners Notified Date Received by ODI Date Added to Database
1980-10-20 1980-05-06 1980-07-18

Production Dates: 1979-07-01 - 1980-01-01

Manufacturers Involved: Mack Trucks, Inc.

Component: PARKING BRAKE:DRIVELINE:AIR

Potential Number Of Units Affected: 9666

Report Initiator: MFR MFR Report

Summary

ON CERTAIN VEHICLES, THE KNOB THAT OPERATES THE TRACTOR PARK VALVE MAY BREAK OFF, RENDERING THE VALVE INOPERABLE.

Remedy

DEFECTIVE KNOBS WILL BE REPLACED WITH AN IMPROVED TYPE, WITHOUT CHARGE TO OWNER.

Notes

VEHICLE DESCRIPTION: TRUCKS.SYSTEM: SERVICE BRAKES; TRACTOR PARK VALVE CONTROL KNOB.CONSEQUENCES OF DEFECT: THE PURPOSE OF THE TRACTOR PARK VALVE IS TO ALLOW THEDRIVER TO APPLY THE TRACTOR SPRING EMERGENCY/PARKING BRAKE INDEPENDENTLY OF THETRAILER EMERGENCY PARKING BRAKES. IF THE KNOB IS BROKEN, THE TRACTOR PARKINGBRAKES CANNOT BE APPLIED. IF PARKED ON AN INCLINE AND LEFT UNATTENDED, VEHICLECOULD ROLL FREE AND CAUSE ACCIDENT AND INJURY.