How to Open the Antifreeze Cap?
2 Answers
The method to open the antifreeze cap is: After parking for half an hour, cover the antifreeze cap with a towel, press down on the cap, and turn it counterclockwise with force. The full name of antifreeze is antifreeze coolant, and its functions are: 1. Provide freeze protection for the engine against low-temperature environments; 2. Prevent the coolant from freezing and cracking the radiator or damaging the engine cylinder block and cylinder head when parking in cold winters; 3. Provide efficient heat dissipation. The steps to replace antifreeze are: 1. Unscrew the radiator cap to drain the antifreeze; 2. Run the engine at idle speed and inject clean water until the radiator releases clean water; 3. After the clean water has drained, close the water valve; 4. Fill with new antifreeze until the liquid level is between the max and min water level marks; 5. Close the cap and let the engine idle for two to three minutes.
I've learned my lesson the hard way when it comes to opening the coolant cap. Back when I first started driving, I didn't know any better and would rush to twist the cap right after turning off the engine. A burst of hot steam nearly scalded my hand. It wasn't until later that I understood you must wait for the engine to cool down completely—like letting it sit for an hour—to allow the pressure to release properly. Locating the expansion tank is usually straightforward; it's typically positioned on the side of the engine bay, with most cars following a similar layout. When unscrewing the cap, do it slowly. A hissing sound is normal as pressure escapes, and only then should you fully open it. Why all this caution? Because the cooling system operates under high pressure when the engine is hot, making quick removal risky. After opening, always check the coolant level—leave it as is if it's adequate, but top up with the correct coolant if it's low. Regular maintenance is key, and avoid mixing coolants of different colors to prevent engine damage.
