Dorman 904-5401CD Diesel Exhaust Fluid (DEF) Filler Cap

DEF Filler Cap Replacement

Dorman 904-5401CD is a diesel exhaust fluid (DEF) filler cap built to match the fit and function of the original cap on specified vehicles. It is a direct replacement for service work where the OE cap is damaged, missing, or no longer sealing properly.

• DEF filler cap for emission control service
• Matches original fit and function on specified applications
• Built for durable, reliable performance in daily use
• Includes retention ring as listed in the package contents
• Cross-references Monroe Shocks & Struts (e.g., 572.3005, 908022301) for the same application

Application Details

Use this Dorman DEF filler cap when servicing emission control hardware on vehicles that require a replacement cap with OE-style fitment. It is a practical choice for DEF tank service on diesel applications where the original cap no longer closes securely or has been lost. Part number 904-5401CD is also a useful search term for buyers looking for a direct replacement DEF filler cap for Dorman 904-5401CD applications.

Common Problems It Can Address

• Missing or damaged DEF filler cap
• Loose or poor-fitting cap at the DEF fill point
• Contamination entering the DEF tank through an unsecured opening
• Service issues caused by a worn original cap

Installation Notes

Confirm the cap style and fill-neck design against the original part before installation. Clean the filler area before fitting the new cap, and verify that the retention ring is seated correctly after installation. For buyers searching by vehicle, this part is commonly referenced for diesel emission control service on Ram 2500 and Ram 3500 DEF filler cap applications, depending on the vehicle’s original equipment configuration.

Quality Assurance

Dorman engineers this replacement cap to match the original part’s fit and function and to deliver dependable service life. Part number 904-5401CD is designed as an OE-style service replacement for specified diesel applications.