Automobile Workshop Safety and Tools
This domain tests workshop discipline and tool knowledge: the personal-protective and fire rules that keep a bay safe, how a vehicle is raised and supported, and how hand tools and torque wrenches are chosen and used. Questions here are practical rather than theoretical.
Safety rules
- PPE: safety shoes, goggles for grinding or chiselling, gloves for hot parts and battery acid.
- Petrol has a flash point near –43 °C, so its vapour ignites at room temperature; store fuel away from sparks and never use petrol to clean parts.
- Exhaust carbon monoxide is odourless; run engines only with the door open and the extractor on.
- Chock the wheels, apply the handbrake, and support a raised vehicle on axle stands, never on a jack alone.
- Disconnect the battery negative lead first and reconnect it last.
- Fire classes: A solids (water, foam), B flammable liquids (foam, dry powder, CO2), C gases (dry powder), E electrical (CO2, dry powder). Water must never go on petrol or live electrical equipment.
Choosing tools
Use a ring spanner or six-point socket on tight nuts, an open-end where space is short, a flare-nut spanner on brake and fuel pipe unions, and a torque wrench for cylinder heads and wheel nuts.
Worked example
A petrol spill ignites near a car in the pit. Which extinguisher? Petrol is Class B; water spreads the burning liquid and adds an electrical risk. Foam smothers it, while dry powder or CO2 knocks the flame down. Reason: choose by fuel class first, then by whether electricity is present.
Traps
Working under a jack; rounding a brake pipe union with an open-end spanner; using water on petrol; leaving the battery connected before welding; using a 12-point socket on a rusted nut; assuming a fire blanket works on a running fuel fire.