Heating and Cooling› Thermostats, Housings and Fillers
Sinister Diesel
Sinister Diesel 01-16 GM Duramax 6.6L Coolant Reservoir (Degas) Cap
SKU: S004 SD-DC-DMAX-01
Moderate — 2–4 hours
Description
Constructed from CNC-machined T6-6061 billet aluminum, this cap features an interior pressure relief system and is rated for 15 PSI. It is available in Anodized Sinister Blue or Gray and includes an etched Sinister Diesel logo.
Fitment
Fitment Guaranteed
Don’t gamble
on fit.
Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.
Available on iOS & Android
Specifications
| Brand | Sinister Diesel |
| Part Number | S004 SD-DC-DMAX-01 |
Buy with Confidence
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
View Full Return Policy