Caps on motor oil bottles, pop bottles and beer bottles keep the liquid in. But a radiator cap is not any ordinary cap. Though it seals the cooling system from the outside, the radiator cap is ...

Cooling systems are pressurized, and the radiator cap is there to manage the pressure. Downflow radiators can only have the cap on the hot side (where hot coolant exits the engine), so this is the ...

Symptom: An engine’s cooling system is overheating. The coolant level is low, but there are no visible leaks and no water in the engine crankcase to hint of water jacket or cylinder head problems.