The defect
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 remedy
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.
NHTSA's own wording · initiated by MFR
Vehicles covered
| Model | Model years |
|---|
Components: SERVICE BRAKES, AIR:ANTILOCK:CONTROL UNIT/MODULE
Other service brakes, air recalls in 1979
19 of the 274 recall campaigns reported to NHTSA in 1979 concerned the service brakes, air; FORD MOTOR COMPANY filed 963 campaigns in all.
| 79V250000 19 Nov 1979 | GRUMMAN FLXIBLE CORP. |
| 79V253000 15 Nov 1979 | HENDRICKSON MFG. CO. |
| 79V248000 15 Nov 1979 | GRUMMAN FLXIBLE CORP. |
| 79V241000 2 Nov 1979 | GRUMMAN FLXIBLE CORP. |
| 79V211000 18 Sept 1979 | INTERNATIONAL HARVESTER |
| 79V216000 13 Sept 1979 | PACCAR, INCORPORATED |
| 79V188000 15 Aug 1979 | TRANSPORTATION MFG. CORP. |
| 79V187000 8 Aug 1979 | GENERAL MOTORS CORP. |
NHTSA recalls (public domain) · all recalls of 1979