Vehicle Mechanical Basics and Maintenance
Candidates should know the routine checks that keep a vehicle safe and the warning signs that mean stop. Daily or pre-journey checks include tyres (pressure and tread depth, including the spare), engine oil, coolant, brake fluid, windscreen washer fluid, lights, mirrors and wipers. Tyre tread must be adequate for grip; worn or unevenly worn tyres reduce braking and steering control. Check pressures when tyres are cold.
Understand what the main systems do: the braking system (including the handbrake and warning light), the steering, the battery and charging system, the cooling system (temperature gauge), and the exhaust. Know the dashboard warning lights: red usually means stop and investigate, amber means caution and check soon. A brake warning light, oil-pressure light or overheating gauge should prompt you to stop safely.
Traps: questions often ask what to do when a warning light appears while driving; the safe answer is usually to stop as soon as it is safe, not to continue home. Another trap is confusing coolant with oil, or checking tyre pressure when tyres are hot. Do not top up a hot engine with cold coolant.
Rule of thumb: red light means stop, amber means check. Worked example: the oil-pressure light comes on while driving; pull over safely, switch off the engine and check the oil level, because continuing can destroy the engine.