Mack · Canada · High
Mack MS300, MS250 +1 more: Brakes
Affects Mack MS300, MS250, Midliner · 1984–1985 — about 146 vehicles.
The hazard
THE AXLE MOUNTED SUPPORT BRACKET FOR THE QUICK RELEASE VALVES MAY CRACK RESULTING IN THE VALVES BEING SUPPORTED ONLY BY STEEL AIR LINES. THIS COULD CAUSE FATIGUE FAILURE OF THE STEEL AIR LINES LEADING TO THE REAR PARKING BRAKES AND CHASSIS SERVICE BRAKES. THE SUDDEN LOSS OF AIR TO THE BRAKE CHAMBERS WILL RESULT IN AUTOMATIC ACTUATION OF THE SPRING LOADED REAR PARKING BRAKE AND SUDDEN REAR WHEEL LOCK-UP. THIS COULD RESULT IN LOSS OF VEHICLE CONTROL AND A CRASH WITHOUT PRIOR WARNING.
What to do
Contact your dealer; the remedy details were not included in the filing.
Critical — crash/injury risk now
High — injury risk; see remedy
Moderate — fix at next service
Low — minor / informational