TMC MC8 1976: SERVICE BRAKES, AIR:SUPPLY
NHTSA Campaign ID Number: 78V008000
| Make | Model | Year |
|---|---|---|
| TMC | MC8 | 1976 |
| Date Owners Notified | Date Received by ODI | Date Added to Database |
| 1977-11-30 | 1978-01-16 | 1979-10-12 |
Production Dates: 1976-08-01 - 1977-10-01
Manufacturers Involved: Motor Coach Industries
Component: SERVICE BRAKES, AIR:SUPPLY
Potential Number Of Units Affected: 527
Report Initiator: MFR MFR Report
Regulation Part Number: 571
Federal Motor Vehicle Safety Standard Number: 121
THE INVOLVED VEHICLES MAY NOT COMPLY WITH FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121, "MODULATED EMERGENCY BRAKING". THE "O" RINGS IN THE SHUTTLE VALVE MAY DEVELOP SLIGHT LEAKS IN COLD WEATHER. IN ADDITION, NEOPRENE WASHERS USED ON THESE "O" RINGS MAY EVENTUALLY EXPAND OR PUCKER IN COLD CLIMATES, MAKING IT POSSIBLE FOR THE SHUTTLE PISTON TO BECOME TRAPPED BY THE INNER-CIRCUMFERENCES OF THE WASHERS. THIS WOULD FORCE THE EMERGENCY BRAKES TO THE "ON" POSITION AND WOULD PREVENT THEM FROM BEING RELEASED.
THE DEALER WILL REPLACE THE TWO NEOPRENE WASHERS WITH GLASS FILLED TEFLON WASHERS THAT WILL NOT BE AFFECTED BY COLD CLIMATES.
VEHICLE DESCRIPTION: BUSES.SYSTEM: EMERGENCY BRAKES; SHUTTLE VALVE.CONSEQUENCES OF DEFECT: SHOULD THE EMERGENCY BRAKES BECOME LOCKED DURINGVEHICLE OPERATION, LOSS OF VEHICLE CONTROL AND AN ACCIDENT COULD RESULT.
