Vehicle safety and pre-trip inspection
This domain tests the pre-trip inspection that makes a passenger bus legally and mechanically ready: lights, tires, brakes, steering, emergency equipment, and defects that must be reported before departure.
Walk-around and engine compartment
Check lights, reflectors, mirrors, windshield, wipers, and horn. Inspect tires for cuts, bulges, tread depth, and proper dual spacing; front tread must be at least 4/32 inch and other tires at least 2/32 inch. Check wheels, lug nuts, and leaks under the engine. Verify oil, coolant, power-steering fluid, belts, and hoses. Secure the hood and baggage doors.
Brakes and safety equipment
For air brakes, build pressure to governor cut-out, shut off the engine, and check leakage: released brakes should lose no more than 3 psi in one minute; applied brakes no more than 4 psi. Confirm the low-pressure warning and spring-brake application. Check the fire extinguisher charge, emergency kit, triangles or fuses, and first-aid supplies. Test parking brake hold.
Worked example
The applied-brake leak test shows 6 psi loss in one minute. That exceeds the 4 psi limit, so the bus is out of service until the leak is found and repaired. A passenger schedule does not justify driving it.
Traps
Missing inner dual damage, forgetting to test the parking brake, and treating a warning lamp as normal are common errors. Report defects; do not sign for a vehicle you have not checked.