Cooling system Pressure Test Kit makes automotive cooling system testing simple, efficient, and economical. It combines our unique hand pressure pump with four cooling system test adapters and two dual-function cap test adapters to quickly reveal external cooling system leaks and detect internal leaks and defective caps. Economical, accurate and simple method to find common causes of overheating. Pinpoints external leaks cause by loose clamps or leaky hoses, connectors, water pumps or radiators. Diagnoses internal leaks causes by a blown head gasket or damaged block or head. Test radiator and coolant bottle caps to ensure they are maintaining the correct pressure. Contains adapters to test the cooling system and caps of most US and Asian cars and light trucks, as well as many European vehicles. Application specific adapters fit the radiator or coolant bottle like the original cap.