The radiator cap is often overlooked in common engine overheating problems. It is designed to add pressure to the cooling system and increase the boiling point like grandma's pressure cooker. A faulty radiator cap can cause your car to boil-over at a lower temperature, but is an easy and inexpensive D-I-Y repair. The Stant SWIV-EL radiator cap design allows the cap to be installed and removed much easier than conventional radiator caps, because the shell of the cap rotates independently from the upper sealing gasket, stem and bottom plate. The octagonal shape is easier to grip than the round OEM design, and is designed to function on open cooling systems and overflow reservoir type systems. Stant offers a wide variety of radiator cap styles and applications for U.S. and import cars, light trucks, HD trucks, racing, off-road and ag equipment