Listing at the top of the most common radiator cap problems, is a defective or busted pressure seal. The internal ring on the underside of the radiator keeps the system pressure in check. If it’s damaged or worn out, the radiator cap may not be able to handle the coolant system’s pressure, which could cause the engine to overheat. It could also cause coolant to leak around the edges of the radiator cap, which can be a hazard, as engine coolant can cause severe injury. Due to the simple design of radiator caps, the only problem one usually experiences with them is a busted seal, unless the cap is physically damaged in some other way.
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