The Radiator Filler Neck Cap helps to maintain the proper pressure within the radiator system, which helps raise the boiling point of the coolant. This prevents premature boiling and overheating, which can damage the engine. The caps are to maintain the optimal pressure within the radiator and cooling system. They have a spring-loaded valve that opens at a specific pressure, allowing excess coolant and steam to escape. Attributes:• Helps to maintain the appropriate pressure balance within the hydraulic system• Prevent the buildup of excessive pressure or the creation of a vacuum• Allow air to escape the system as the coolant expands with heat while preventing coolant lossApplications:The Radiator Filler Neck Cap is used to prevent the system from overheating and boiling over. The cap protects the cooling system components from damage due to exposure to hot, acidic coolant.