Ministry of Transportation / Ministère des Transports
Home > Bus Handbook > Road test > Daily inspection test
Text size Enlarge Text Shrink Text
Search   |  
Daily inspection test
Exterior Items

4. Low-air warning system fails or system is activated

You must know the proper method for testing the low-air warning, and that a vehicle has this major defect when the low air-warning fails to activate or activates before air pressure drops below 55 psi.


    • Ensure air pressure is above 621 kPa (90 psi). If air pressure is too low, warning may activate as soon as ignition key is turned on.
    • Ensure ignition key is turned on. Engine may be running or shut off (If ignition key is not turned on, the warning will not activate)
    • Press and release the brake pedal (to lower pressure) several times until warning activates.
    • Watch the pressure gauges and note the pressure when the low-air warning device activates (Low-air warning device may be only a light, or a light and an audible device.)