Practice question

What should you do before removing the radiator cap on a pressurized system?

  1. Remove it immediately to check the coolant level
  2. Wait until the system has cooled
  3. Check the pressure gauge first
  4. Loosen it slowly while the engine is running

Answer: B — Wait until the system has cooled

Before removing the radiator cap on a pressurized system, it is important to wait until the system has cooled. This is because the coolant inside the system is heated to high temperatures and can be under pressure. If you remove the cap while the system is hot or pressurized, you risk being sprayed with hot coolant and steam, which can cause serious burns and injuries. Waiting for the system to cool down allows the pressure to drop and the temperature of the coolant to decrease, making it safer to open the cap. It’s also a good practice to open the cap slowly to release any remaining pressure gradually, further reducing the risk of injury. This precaution is critical to ensure safety for anyone performing maintenance on the vehicle.

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