The defect
THE RETAINING PIN FOR THE BRAKE CONTROL KNOB HAS BEEN MISALIGNED (OFF THE CENTER LINE OF THE VALVE PLUNGER HOLE). THIS CAUSES THE KNOB TO BE OVERSTRESSED AT THE RETAINING PIN HOLE AREA CAUSING IT TO SEPARATE FROM THE VALVE.
The remedy
THE HOLES WILL BE RETOOLED TO PROVIDE CORRECT ALIGNMENT AND PLASTIC KNOBS WILL BE REPLACED BY KNOBS OF STRONGER MATERIAL HAVING METAL REINFORCEMENTS.
NHTSA's own wording · initiated by MFR
Vehicles covered
| Model | Model years |
|---|
Components: SERVICE BRAKES, AIR:CONTROLS:HAND CONTROL/VALVE
Other service brakes, air recalls in 1981
4 of the 157 recall campaigns reported to NHTSA in 1981 concerned the service brakes, air; MACK TRUCKS, INCORPORATED filed 245 campaigns in all.
| 81V133000 20 Oct 1981 | TRANSPORTATION MFG. CORP. |
| 81V097000 12 Aug 1981 | FREIGHTLINER CORP. |
| 81V046000 7 Apr 1981 | FWD CORPORATION |
NHTSA recalls (public domain) · all recalls of 1981