Multiple U.S. Warehouse LocationsBroken ApexFree shipping on qualified orders over $100*
The Sinister Diesel Coolant Reservoir (Degas) Cap fits 2001–2016 GM Duramax 6.6L coolant reservoirs as a durable replacement for failure-prone factory caps. CNC-machined from T6-6061 billet aluminum with an interior pressure relief system, it’s rated for 15 PSI and is available in anodized Sinister Blue or gray, combining reliable pressure control with custom styling.
Sinister Diesel 01-16 GM Duramax 6.6L Coolant Reservoir (Degas) Cap
