Gates 30002 Diesel Exhaust Fluid (DEF) Filler Cap

Gates DEF Cap for Diesel Exhaust Fluid Fill Necks

The Gates Diesel Emissions Fluid (DEF) Cap, part number 30002, is a non-locking filler cap for diesel exhaust fluid tanks. It helps seal the DEF filler neck to reduce spills and keep dirt and debris out, while the blue cap color makes the DEF fill point easier to identify during service.

Built as a Gates DEF Cap with quick-on attachment, vented construction, and OE performance comparison rating, this cap is a direct service part for technicians working on diesel emissions systems. It is a practical choice for Ford Super Duty, Ram 2500, and Freightliner-style DEF service applications where clear identification of the DEF tank matters.

Key Features

• Gates Diesel Emissions Fluid (DEF) Cap, part number 30002
• Non-locking design for quick service access
• Vented cap construction
• Quick-On cam type attachment
• Blue cap color helps identify the DEF filler neck
• OE performance comparison rating
• Neck diameter: 1.57 in; shell diameter: 2.56 in; cap depth: 0.67 in

Detailed Description

The Gates 30002 DEF filler cap is made for diesel exhaust fluid reservoirs that use a quick-on style cap with a 1.57-inch neck diameter. Its vented, non-locking design helps maintain a secure seal at the filler neck while allowing normal tank service, and the blue color supports fast visual identification in the shop. For diesel trucks and commercial vehicles, that clear identification matters when servicing Ford Super Duty, Ram 2500, and similar DEF-equipped platforms.

This Gates Diesel Emissions Fluid (DEF) Cap is designed to keep foreign material out of the tank and reduce the chance of contamination-related repairs. If you are replacing a worn or missing DEF cap on a diesel pickup or medium-duty application, part number 30002 provides a straightforward OE-style service solution. This part cross-references Dorman - HD Solutions 904-5201 for the same application.

What It Helps Solve

• DEF spills or seepage through the filler neck
• Dirt and debris entering the diesel exhaust fluid tank
• Misidentification of the DEF fill point during service
• Contamination from foreign fluids in the DEF system
• Worn, missing, or damaged filler caps on diesel vehicles

Installation Notes and Tips

Confirm the filler neck uses a 1.57-inch diameter and quick-on cam-style cap before installation. Match the vented, non-locking design to the original cap style, and inspect the filler neck for damage or contamination before fitting the new cap. For Ford Super Duty, Ram 2500, and other DEF-equipped diesel applications, verify the cap seats fully and closes securely after service.

Quality Assurance

Gates supplies OE-performance replacement components for automotive fluid and emissions service. The 30002 DEF cap is built to meet the needs of diesel emissions maintenance with the fit and function expected for routine shop use.