The Gates 31521 Radiator Cap keeps you Ready for the Road Ahead being built to last with its corrosion-resistant, heavy gauge metal. Experience long service life and precise pressure control, while offering a wide range of pressures. With this precise pressure control, no adjustment is required for installation. This Gates radiator cap is designed to raise the radiator fluid’s boiling point in order to avert premature boiling and overheating in your cooling systems, maintaining your active road time. FleetPride is your First Click in Heavy Duty .