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Signs of a Faulty Radiator Pressure Cap

The radiator pressure cap is a two-valve part that holds coolant and keeps the radiator system pressurized. Typically, the pressure found inside the radiator is 16 pounds per square inch and the radiator cap is the piece that controls that pressure. If the pressure is not constant, your vehicle could run the risk of overheating and can also cause crippling damage to the radiator.

There are a few ways to detect if your radiator cap is malfunctioning. Below is a list of what to look out for.

Engine Overheating

If your engine is overheating, there more than likely is a problem with the coolant and it leaking. As the engine temperature rises, make sure to turn off the car before you inspect under the hood. Once the engine is cool, you may notice coolant around the cap. The coolant could be escaping because of the radiator pressure cap. Inspect it for any damages.

Coolant Leak

A stuck radiator cap will not be able to release fluid, allowing pressure build up. This pressure can cause the radiator hose to burst or create leaks.

Check for any coolant leaks coming from around the cap or the radiator. If there are any holes in the radiator, inspect the cap for any defaults as this can be a sign it is needing to be replaced.

Boil Over

Your vehicle’s reservoir tank contains coolant. The pressure in the radiator releases the cap and sends the fluid to the tank. If your cap is not functioning correctly, the coolant will be released to quickly and can overflow the reservoir tank. If you experience this boil over, check the cap for damage.

Air in the Cooling System

If the radiator pressure cap is not on correctly, air will enter the cooling system. When the air enters, it creates smaller compartments of air inside the hoses, heater core and thermostat. The heater will be unable to function because of the air and will cause overheating. Buying the correct radiator pressure caps can easily help prevent this problem from happening.

Collapsed Radiator Hose

If your radiator hose has collapsed, this could also be a result of a faulty cap. If your radiator cap does not let go of the vacuum the way it is supposed to, you could see it affecting the radiator hose as it cools down. Again, check your radiator pressure cap for any damage and replace as soon as possible.