TL*THE CONTACT OWNS A 2001 NEW FLYER LOW FLOOR BUS. THE VEHICLE WOULD NOT STOP WHEN THE BRAKE PEDAL WAS DEPRESSED. A MECHANIC STATED THAT SOMETHING IN THE AIR SYSTEM IS MOMENTARILY REDUCING THE AMOUNT OF AIR THAT IS RECEIVED THROUGH THE HYDRAULIC BRAKING SYSTEM. ON ONE OCCASION, THE FAILURE CAUSED THE CONTACT TO CRASH INTO A TREE. SEVERAL OCCUPANTS REPORTED MINOR INJURIES. THE DRIVER STATED THAT THE ABS WARNING INDICATOR WAS ILLUMINATED ON THE INSTRUMENT PANEL. THE MANUFACTURER DID NOT ASSIST. THE VIN AND MILEAGES WERE UNKNOWN.