Dorman 904-133 Fuel Injector O-Ring Kit

Dorman 904-133 Fuel Injector O-Ring Kit

Dorman 904-133 is a fuel injector O-ring kit for specified Chevrolet Silverado 2500 HD, Chevrolet Silverado 3500, GMC Sierra 2500 HD, and GMC Sierra 3500 applications from 2001-2004. It includes the seals needed for a full injector-related replacement on the listed engine, using rubber components built to handle fuel, oil, and elevated temperatures.

Key Features

• Fuel injector O-ring kit for specified GM truck applications
• Rubber construction with a black finish
• Round O-ring profile for injector sealing service
• Includes fuel rail gaskets, return line gasket, O-rings, and crush washers
• Direct replacement service kit for injector seal maintenance

Detailed Description

This Dorman fuel injector O-ring kit, part number 904-133, is built for service work on 2001-2004 Chevrolet Silverado 2500 HD and Silverado 3500, as well as 2001-2004 GMC Sierra 2500 HD and Sierra 3500 models. The seals are made from durable rubber to resist exposure to fuel, oil, and extreme operating temperatures, helping restore sealing integrity at the injector, fuel rail, and return line interfaces. If you are servicing a Chevrolet Silverado 2500 HD fuel injector seal leak or replacing worn injector seals on a GMC Sierra 3500, Dorman 904-133 provides the correct service components for the listed application.

This part cross-references 2H-56090 and 274787 for the same application.

What It Is Used For

• Repairing fuel seepage around injector sealing points
• Replacing hardened or cracked injector O-rings
• Addressing fuel rail gasket wear during injector service
• Restoring sealing at the return line connection
• Supporting maintenance on GM truck fuel delivery systems

Installation Notes and Tips

Confirm engine application before installation and compare the removed seals to the new components for size and profile. Clean all sealing surfaces thoroughly, lubricate new rubber seals with clean engine oil or approved fuel-system lubricant, and inspect injector bores, fuel rail surfaces, and return line contact points for damage before reassembly. For 2001-2004 Chevrolet Silverado 2500 HD and GMC Sierra 2500 HD fuel injector service, replacing all related seals at the same time helps reduce repeat leaks.

Quality Assurance

Dorman manufactures this kit with materials selected to withstand fuel, oil, and high-temperature exposure in demanding engine environments. The part is engineered as a service replacement for the specified GM truck applications and is backed by Dorman’s product quality standards.