General Knowledge: Vehicle Inspection and Basic Control
What this section tests
Inspection and basic-control questions make up a large share of the General Knowledge item bank. You are expected to say what you check and why, not merely name parts.
The seven-step pre-trip
- Vehicle overview: damage, leaks, missing parts.
- Engine compartment: belts, hoses, coolant and oil levels, power steering, brake lines.
- Walk-around: lights and reflectors checked at the front, driver's side, rear, and passenger side.
- Steering, suspension, brakes: tie rods, springs, brake chambers, slack adjusters, hoses.
- In-cab: gauges, controls, mirrors, seat belt, emergency equipment.
- Brake tests: static air leak-down, applied leak, parking brake hold.
- Start the engine, watch the gauges, listen for problems, then road test.
Basic control rules
- Build full air pressure before moving; stay alert for the low-pressure warning until the gauge passes roughly 60 psi.
- Release the parking brake completely and confirm the warning buzzer and lights go out.
- Start in the right gear, check mirrors and blind spots, and signal before merging.
- Never coast and never leave the seat with the vehicle able to roll.
Worked example
A combination vehicle holds 120 psi with the engine off and the parking brakes released. After one minute the gauge reads 116 psi. The leak limit for a combination is 4 psi per minute (3 psi for a straight truck), so this sits at the limit. It passes only if the applied test - brakes on, 6 psi limit for a combination and 4 psi for a single vehicle - and the parking brake check also pass.
Traps
- Swapping the single-vehicle and combination leak limits.
- Treating the pre-trip as a quick walk-around; the in-cab and brake steps are examined too.
- Forgetting to mention a defect you found, or skipping the road-test step entirely.