Dorman 904-7998 Diesel Exhaust Fluid (DEF) Pump Cover

DEF Pump Cover for Emission Control Protection

Dorman 904-7998 is a diesel exhaust fluid (DEF) pump cover built to replace a missing or damaged original cover on specified vehicles. It helps shield the DEF pump from road debris and exposure to the elements while maintaining OE-style fit and function.

Compatible With select diesel applications where the original DEF pump cover has been damaged, this replacement is formed from metal with a black housing finish and mounts with a bolt attachment method. It is a practical choice for owners searching for a DEF pump cover for Dodge Ram diesel models, Ram 2500 DEF pump cover replacement, or a direct-fit emission control cover under part number 904-7998.

• Direct replacement for a missing or damaged DEF pump cover
• Metal housing construction with black finish
• Designed to match original fit and function on specified vehicles
• Three mounting holes with 10.8 mm diameter
• Measures 268.2 mm long and 261 mm wide
• Part number 904-7998 for catalog and cross-reference use

Detailed Product Overview

This Dorman DEF pump cover is part of the emission control system and is engineered to restore the protective barrier around the DEF pump. By covering the pump assembly, it helps reduce direct exposure to road spray, debris, and weather-related wear. The cover is intended for vehicles that originally used this style of DEF pump shield, making it a straightforward replacement for service work on diesel trucks and other diesel-equipped applications. If you are searching for a Dodge Ram DEF pump cover, Ram 2500 emission component, or Dorman 904-7998 replacement cover, this part is built for that type of repair.

This part cross-references 564.46658 and 0427658000 for the same application.

Common Problems This Part Can Address

• Missing DEF pump cover after prior service or damage
• Cracked or corroded original cover
• Exposure of the DEF pump to road debris
• Damage from moisture, salt, and weather exposure
• Need for an OE-style emission component replacement

Installation Notes and Tips

Verify the vehicle’s original DEF pump cover dimensions, mounting hole count, and attachment style before installation. This cover uses a bolt attachment method and does not include mounting hardware, so reuse or source the correct fasteners as needed. Confirm clearance around the DEF pump assembly and compare the old cover to the new part before final tightening.

Quality Assurance

Dorman designs replacement emission components to match the fit and function of the original part on specified vehicles. Part number 904-7998 is built as a direct replacement DEF pump cover for service applications where the factory cover is missing or damaged.