Never remove the radiator cap while the engine is running, or when the engine and radiator are hot. Scalding coolant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system.
Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap.
Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes.
When you are sure all the pressure is gone, press down on the cap using the cloth, turn it, and remove it.
1. Clean the radiator cap negative pressure valve and tha sealed part.
2. Inspect the crack or turn over on sealed of the radiator cap.
If not as specified, repace the radiator cap.
3. Fill the radiator cap test adopter with the water or the engine coolant to the full level and attach the radiator cap to the adapter.
4. Hold the radiator cap downward and apply pressure gradually. Verify that the pressure become held for 10 s
within the specification.
If the pressure will not stable within the specification, replace the radiator cap.