The Sinister Diesel Coolant Radiator Surge Tank Cap is a direct-fit replacement designed specifically for Chevy/GMC trucks equipped with the Duramax L5P engine. Made from quality, corrosion-resistant materials and engineered for a secure seal, this upgraded cap helps maintain proper cooling system pressure while keeping contaminants out of your coolant reservoir.

Easy to install with no tools or modifications required, this surge tank cap is an affordable way to improve reliability and complete the look of your engine bay on your Duramax powered truck.