Sinister Diesel 01-16 GM Duramax 6.6L Coolant Reservoir (Degas) Cap

If you're working on a 2001-2016 GM truck with a 6.6L Duramax engine, this coolant reservoir cap from Sinister Diesel is a solid option to replace your factory cap. It's designed to function just like the original, but with a custom look and improved materials. This cap is essential for maintaining the correct pressure in your cooling system, which helps prevent overheating and ensures your engine runs smoothly.

This cap is CNC machined from T6-6061 billet aluminum, making it a well-built replacement for the factory part that can be prone to failure. It features an interior pressure relief system that will continue to function even if the gasket has issues, offering added reliability. The cap is rated for 15 PSI, which is the standard for many Duramax cooling systems, and it comes etched with the Sinister Diesel logo. You can choose between a gray finish or an anodized Sinister Blue, both of which add a custom touch under the hood.

This cap fits a wide range of GM trucks, including the Chevrolet Silverado 2500 HD and 3500 HD, as well as the GMC Sierra 2500 HD and 3500 HD models from 2001 through 2016. It's a direct replacement for the factory cap and includes one Sinister Diesel Coolant Reservoir Cap in the package.