NHTSA Recall 75V192000
Filed by Mack Trucks, Inc.. Component: Service Brakes, Air. Reported 1975-10-31. An estimated 1,200 vehicles are affected. Recall repairs are free at any authorized dealer.
Defect
MACK CAMPAIGN NO N/A.TRUCKS WITH DUAL BRAKE TREADLE VALVE PIPING SEPT.1974AND MAR.31, 1975.POSSIBILITY THAT THE PRIMARY AND SECONDARY AIR SUPPLYLINES MAY HAVE BEEN CONNECTED IN REVERSE AT THE DUAL BRAKE TREADLE VALVE.THEREVERSING OF THESE SUPPLY LINES DOES NOT IN ITSELF, AFFECT VEHICLE BRAKING IFBOTH THE PRIMARY AND SECONDARY AIR SUPPLY SYSTEMS HAVE NORMAL OPERATING AIRPRESSURE.HOWEVER, IN THE EVENT OF LOSS OF AIR PRESSURE IN EITHER THE PRIMARYOR SECONDARY SYSTEM, NEITHER THE PRIMARY NOR SECONDARY SERVICE BRAKES WOULDFUNCTION WHEN APPLIED.IN THIS EVENT, IT WOULD REQUIRE MANUAL APPLICATION OFTHE EMERGENCY SPRING BRAKE TO STOP VEHICLE.(CORRECT BY INSPECTING ANDREROUTING AIR SUPPLY PIPING AS REQUIRED TO CORRECT SYSTEM).