School Bus Vehicle Inspection, Braking, and Special Driving Situations
School Bus Vehicle Inspection, Braking, and Special Driving Situations
This domain tests the pre-trip inspection, the air-brake checks that appear on the CDL skills test, and the driving adjustments Illinois expects in bad weather.
Inspection
Check lights, stop arm, crossing gate, mirrors, tires and tread, wheels, brakes, emergency exits, first aid kit, fire extinguisher, seat belts, and fluid leaks. Test the stop arm and red lights; a failed stop arm means the bus is out of service.
Air brakes
With a fully charged system and the engine off, release the parking brake and watch the gauge for one minute; a loss of more than 3 psi indicates a leak. Apply the brake and hold for one minute; more than 4 psi is a leak. The low-pressure warning must come on before 60 psi, and the spring brakes should set between 20 and 45 psi. Build-up from 85 to 100 psi should take about 45 seconds at fast idle.
Special driving
Downhill: select a lower gear before the descent and use engine braking; do not ride the brakes. Fog: low beams, slow down, increase following distance. Ice: gentle steering and braking, no cruise control. High winds: grip the wheel, reduce speed, and watch for the bus being pushed.
Worked example
During the pre-trip, the low-pressure warning does not sound until 30 psi. Reasoning: the warning is required well before 60 psi, so the test fails. The driver documents the defect and does not drive the bus; the warning is a safety system, not a suggestion.
Traps
Skipping the leak-down tests; assuming ABS shortens stopping distance on ice; descending a grade in high gear; ignoring a cracked mirror because the bus still drives.