Continental Belts And Hoses - Pressure and Heat: Replace The Weakest Link

Most late model cars and trucks are designed to operate at 18 to 21 PSI, or less. So most radiator and heater hoses never see the high side of 21 PSI, even if the engine runs hot and overheats. The spring-loaded valve inside the radiator cap will open at its maximum rated pressure and vent steam and coolant to relieve pressure.