CERTAIN AIR BRAKE ANTI-LOCK MODULATORS COULD MALFUNCTION DURING OPERATION OF THE ANTI-LOCK SYSTEM
— Recall Campaign #79V077000
CERTAIN AIR BRAKE ANTI-LOCK MODULATORS COULD MALFUNCTION DURING OPERATION OF THE ANTI-LOCK SYSTEM. A NYLON PISTON WITHIN THE MODULATOR AIR VALVE SYSTEM CAN SWELL FROM EXPOSURE TO SYSTEM CONTAMINANTS. CONTINUED EXPOSURE MAY CAUSE THE PISTON TO SWELL TO THE EXTENT THAT INTERFERENCE WITH THE CYLINDER WALL WILL RESULT, CAUSING MOMENTARY STICKING OR A PERMANENT JAM. THIS CAN RESULT IN TEMPORARY OR PERMANENT LOSS OF BRAKING FOR THE AFFECTED AXLE.
The recall was influenced by the manufacturer with about 65,000 units affected.
NHTSA Safety Recall Notice
79V077000
| Manufacturer: | Ford Motor Company |
|---|---|
| Recall date: | March 29, 1979 |
| NHTSA Campaign #: | 79V077000 |
| Units affected: | 65,000 |
- Description:
- CERTAIN AIR BRAKE ANTI-LOCK MODULATORS COULD MALFUNCTION DURING OPERATION OF THE ANTI-LOCK SYSTEM. A NYLON PISTON WITHIN THE MODULATOR AIR VALVE SYSTEM CAN SWELL FROM EXPOSURE TO SYSTEM CONTAMINANTS. CONTINUED EXPOSURE MAY CAUSE THE PISTON TO SWELL TO THE EXTENT THAT INTERFERENCE WITH THE CYLINDER WALL WILL RESULT, CAUSING MOMENTARY STICKING OR A PERMANENT JAM. THIS CAN RESULT IN TEMPORARY OR PERMANENT LOSS OF BRAKING FOR THE AFFECTED AXLE.
- Consequeces:
- Corrective action:
- THE PISTONS IN THE VALVE PORTION OF THE MODULATORS WILL BE REPLACED WITH PISTONS THAT DO NOT SWELL WHEN EXPOSED TO AIR BRAKE SYSTEM CONTAMINANTS.
- Notes:
- VEHICLE DESCRIPTION: HEAVY TRUCKS EQUIPPED WITH ANTI-LOCK AIR BRAKECONTROLLERS.SYSTEM: SERVICE BRAKES; CONTROL ASSEMBLY.