Radiator Caps As the engine’s coolant heats, it expands, increasing pressure inside the closed coolant system. The radiator cap controls this expansion and provides constant pressure on the system.
What happens if my radiator cap is broken?
When your radiator cap does not seal properly, air could make its way inside of the cooling system. This will cause air pockets to get inside of the heater core, thermostat, and radiator hoses. As a result, the engine will start to overheat because it cannot sustain a temperature that is consistent.
How do I know what size radiator cap I need?
Know the Pressure Rating Each cap is different depending on the model of your car. The owner’s manual often has the correct pressure rating listed that is necessary for your car. If the pressure rating is not listed in the owner’s manual, it will be under the hood on top of your old radiator cap.
Where is the radiator cap?
Is coolant in the radiator?
Car coolant is located in a reservoir affixed to the radiator before it’s introduced to the engine block and its components. Engine coolant is used in conjunction with a liquid cooling system.
How do you pressure test a radiator cap?
To test the radiator cap with the hand pump, attach the cap to the pump using the proper adaptor and operate the pump until the cap starts to release pressure. Note the reading on the cap to see if it is releasing at the proper pressure. Stop increasing the pressure.
Can a bad coolant reservoir cap cause overheating?
A faulty radiator cap can result in engine overheating, loss of coolant or major engine damage. So, Pressurized cooling systems help prevent overheating and coolant loss. Also, It raises the coolant boiling point about 3-degrees F for each additional psi above atmospheric pressure.
Why is my coolant leaking from the cap?
If the cap isn’t releasing excess pressure properly, that pressure can force the coolant to leak out at the point of least resistance. This can be from the cap, a hose, engine gaskets, the water pump or even from the radiator itself, especially if you have an older vehicle with lots of miles on it.
Can a loose radiator cap cause overheating?
A loose radiator cap will cause the system not to pressurize, resulting in overheating. In this case, the coolant is more likely to be lost to boiling off than by simple evaporation.
How do you put a reservoir cap on?