THE HYDRAULIC BRAKE SYSTEM ON THESE BUSES USES TWO HYDRAULIC PRESSURE SWITCHES TO OPERATE THE BRAKE LIGHTS AND THE BRAKE BOOSTER PUMP. THE BRAKE PRESSURE WARNING LIGHT CAN ACTIVATE WHEN ACTUAL SYSTEM FAILURE HAS NOT OCCURRED.
Consequence & remedy
Consequence: A FALSE WARNING OF THE BRAKE PRESSURE WARNING LIGHT CAN CAUSE THE DRIVER TO IGNORE A WARNING WHEN AN ACTUAL PROBLEM EXISTS WHICH COULD RESULT IN AN ACCIDENT.
Remedy: DEALERS WILL REPLACE THE TWO HYDRAULIC PRESSURE SWITCHES WITH ONE MECHANICAL SWITCH THAT IS ACTIVATED BY BRAKE PEDAL STROKE.
THE PRESSURE RELIEF VALVE WAS OMITTED IN THE AIR TANK. THE AIR TANK IS THE RESERVOIR FOR THE AIR SUSPENSION AND IS NOT BRAKE RELATED. WITHOUT THE PRESSURE RELIEF VALVE, THERE IS NO BACK-UP SYSTEM TO LIMIT AIR PRESSURE IN THE AIR SUSPENSION SYSTEM.
Consequence & remedy
Consequence: LACK OF A BACK-UP SYSTEM TO LIMIT AIR PRESSURE BUILD UPCAN CAUSE EXCESSIVE PRESSURE IN THE AIR TANK AND CAN CAUSE THE TANK TO RUPTURE.THIS CAN RESULT IN PERSONAL INJURY TO ANYONE IN THE VICINITY.
Remedy: INSTALL A PRESSURE RELIEF VALVE IN THE AIR TANK.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
1993 International Harvester 3900FC Problems, Complaints & Recalls | Skip That Year