Commercial Vehicle Operation and Vehicle Inspection
Pre-trip inspection is the core skill
A professional driver inspects the vehicle before every trip. The purpose is to catch defects that could cause a breakdown or crash before the wheels roll. A complete inspection walks around the vehicle in a set order and checks: tires (tread depth, cuts, bulges, proper inflation, dual-tire spacing), wheels and fasteners (cracks, loose lug nuts, rust streaks indicating movement), brakes and air lines, lights and reflectors, mirrors, windshield and wipers, fluid levels, belts and hoses, coupling devices, cargo securement, and emergency equipment.
The walk-around method
Use a consistent pattern, such as starting at the driver's door and moving clockwise. Consistency prevents skipped items. Check the engine compartment with the engine off: coolant, oil, power-steering fluid, washer fluid, belts (fraying, glazing, cracks), and hoses (soft spots, leaks). Start the engine and watch the gauges: oil pressure should rise, the voltmeter should read in the normal range, and the air pressure should build. Test the lights with a helper or by reflection, and check the coupling and safety latches on trailers.
The traps
- "The mechanic checked it last week." The driver is responsible for the vehicle's condition on each trip; a recent shop visit does not replace the pre-trip inspection.
- Dual tires. Mismatched sizes or badly unequal inflation cause the larger tire to carry more load and overheat; know that duals must match.
- Brake adjustment and air loss. Know that a vehicle with a defect affecting safety must be placed out of service until repaired.
- Post-trip reports. Defects found after a trip must be reported so they can be fixed before the next trip.
Rule of thumb
If you find a defect that affects safe operation, do not drive. Document it, report it, and keep the vehicle out of service until it is repaired.