MACK R 1975: SERVICE BRAKES, AIR:SUPPLY:HOSES, LINES/PIPING, AND FITTINGS
NHTSA Campaign ID Number: 75V192000
| Make | Model | Year |
|---|---|---|
| MACK | R | 1975 |
| Date Owners Notified | Date Received by ODI | Date Added to Database |
| 1976-02-20 | 1975-10-31 | 1979-10-12 |
Production Dates: 1974-10-01 - 1976-03-01
Manufacturers Involved: Mack Trucks, Inc.
Component: SERVICE BRAKES, AIR:SUPPLY:HOSES, LINES/PIPING, AND FITTINGS
Potential Number Of Units Affected: 1200
Report Initiator: MFR MFR Report
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'.
