Radiator Cap

Simply put, Radiator Cap is the cap on the opening in the top of a radiator through which a coolant liquid can be added. But it is more than just a simple lid, it keeps the engine cool by sealing and pressurizing the coolant inside it.

Characteristics of Radiator Cap
Some of the most important characteristics of these Caps are:

• It is designed to hold the coolant in the radiator under a predetermined amount of pressure.
• Though pressure inside the radiator is necessary to keep the engine cool, too much of pressure can make the cap to blow off. To prevent this, it has a pressure relief valve which allows it to take up just a certain amount of pressure.
• Most Radiator pressure caps are not meant to be removed. Coolant should always be added through the expansion tank.

Functions of Radiator Cap

• It keeps the coolant inside the radiator under pressure thus preventing it from boiling away.
• The pressure valve in the radiator cap helps to keep the right pressure in the radiator.

Materials used for making Radiator Cap
Materials used for making these caps are:

• Stainless Steel
• Aluminum

Maintenance of Radiator Cap

• It should be opened only when the engine is cold, otherwise steam can shoot out and burn.
• It can be tested using an adapter to ensure that it is up to the pressure rating and should be replaced if it fails.