Q:

What are the symptoms of a bad radiator cap?

A:

A bad radiator cap can cause the coolant to boil over from the reservoir or the engine to overheat. The cap is an integral piece of an engine's cooling system as it retains the coolant´s pressure.

Know More

Full Answer

A radiator caps primary function in a cooling system is to retain the engine´s cooling system pressure. A standard cap will have a weight scribed on top of it. The number refers to the boiling point which is increased by degrees for every pound written on the cap. For example, a cap rated at 15 pounds will increase the boiling point of coolant an extra 30 degrees. Listed below are the symptoms of a bad radiator cap.

Reservoir boils over

The reservoir tank is where the coolant flows when it expands. Pressure releases the radiator cap which sends the coolant to the overflow tank. A faulty cap will release the coolant too soon resulting in an overflowing reservoir.

Air in the system

If the cap does not properly seal the cooling system, air will enter it. When air enters the system pockets form inside the cooling hoses, thermostat and heater core. When there is air in the system the heater will fail to produce heat and the engine will not be able to retain a consistent temperature, which will cause it to overheat.

Learn more in Car Parts & Maintenance

Related Questions

  • Q:

    How do you flush a radiator?

    A:

    Flush your vehicle's radiator by draining the coolant, refilling it with chemical flush product and water, starting the vehicle and bringing it to operating temperature, draining a second time, and refilling the radiator with an antifreeze mix. This job completes in the span of an afternoon.

    Full Answer >
  • Q:

    How do you replace a radiator?

    A:

    To replace a radiator, remove the coolant, disconnect and remove the old radiator from the engine compartment. Install the new radiator, and fill it with coolant.

    Full Answer >
  • Q:

    How do I put antifreeze in a radiator?

    A:

    To add antifreeze to the radiator reservoir, unscrew the reservoir cap, and pour the coolant in the reservoir tank until it reaches the full line. You need antifreeze, otherwise known as radiator coolant, that is one part coolant and one part water. Do not remove the reservoir cap if the engine is still hot.

    Full Answer >
  • Q:

    How does a radiator overflow tank work?

    A:

    A radiator overflow tank collects the expanding coolant that is heated by the engine and recycles it back into the coolant system once it loses enough heat. The radiator overflow tank works in conjunction with the radiator cap to protect the engine and prevent coolant loss due to overflow, according to HowStuffWorks.

    Full Answer >

Explore