When working on a vehicle's cooling system, which component requires caution when opening to avoid burns?

• A. Radiator cap
• B. Oil filler cap
• C. Gas cap
• D. Hood latch

Answer: (A)

Opening the cooling system component with the main risk of burns is the radiator cap. The cooling system is filled with hot, pressurized coolant, and the radiator cap is what seals and maintains that pressure. When the engine is hot, releasing that pressure suddenly can cause hot coolant and steam to spray out, leading to serious burns. To avoid this, wait for the engine to cool before touching the cap, and open it slowly (often using a rag) to vent any remaining pressure gradually.

The other items aren’t part of the cooling system’s pressurized path. The oil filler cap covers engine oil, which isn’t under the same pressure from the cooling system; opening it when hot can cause oil to splatter but not the same steam-burn risk. The gas cap is for fuel vapor and is unrelated to the cooling loop. The hood latch simply opens the hood and isn’t involved in handling hot pressurized coolant.