NHTSA Campaign Id 75V193000; Date: Oct. 31, 1975
1974 Mack F; 1975 Mack F
Component: Service Brakes, Air:supply:hoses, Lines/piping, And Fittings
Manufactured by: Mack Trucks, Incorporated
Affected Units:: 2,250
Mack campaign no q1012. Trucks sept. 2, 1974 thru July 30, 1975. Possibilitythat an error was made in the installation of the air supply piping to thetractor trailer park valve manifold. If this occurs, the primary air supplysystem becomes the sole source for supply air to the tractor trailer park valvein this condition, tractor or trailer brake operation is not affected, as longas the primary system has normal operating air pressure. However,in this couldbe hazardous to either the primary system, there will be a corresponding lossof air to the tractor trailer park valve0 and this valve, by design, willautomatically apply the emergency spring brakes, which then could only bereleased mechanically. An automatic application of the emergency spring brakeswould immobilize the vehicle and require mechanical release wheel by wheel. This could be hazordous to either the vehicle operator or to the individualreleasing the brakes. (correct by inspecting and changing piping to proper airsupply system).
Date Owners notified by Manufacturer: Mar 1, 1976
Also see: