Mahle GS33877 Fuel Injector O-Ring Kit - Upper and Lower

Fuel Injector Sealing for Direct Injection Service

The Mahle Fuel Injector O-Ring Kit GS33877 provides OE-standard sealing components for fuel injector service on select Ford and Lincoln applications. Built with fluoroelastomer material and finished in black, this kit is made for upper and lower injector sealing points where precise fit and fuel resistance matter.

Mahle GS33877 is a practical choice for restoring injector seal integrity on vehicles such as the Ford F-150 and Ford Edge, as well as Lincoln Nautilus and Navigator applications. It is built around the Mahle Fuel Injector O-Ring Kit product line, which focuses on sealing components used in demanding engine service work.

Key Features

• Fluoroelastomer construction for fuel-system sealing applications
• OE Standard item grade for service replacement use
• Includes upper fuel injector O-rings, lower fuel injector Teflon seals, and fuel injector support rings
• Black finish for easy identification during service
• Designed for upper and lower injector sealing points
• Cross-references Ford BL3Z-9229-B and Motorcraft CM-5209 for the same application

Detailed Product Overview

Mahle GS33877 is a fuel injector O-ring kit engineered for service on direct-injection and standard injector sealing systems where the injector must seal cleanly at both the upper and lower locations. The fluoroelastomer material is selected for fuel exposure, while the OE-standard construction supports accurate replacement during injector maintenance. Dimensions listed for the sealing components include a 0.229 inside diameter, 0.140 thickness, and 0.511 outside diameter.

This kit is a direct fitment option for multiple Ford and Lincoln platforms, including 2018-2020 Ford F-150, 2015-2021 Ford Edge, 2022-2024 Ford Edge, 2019-2021 Lincoln Nautilus, and 2015-2017 Lincoln Navigator. It is also listed for 2015-2020 Ford Transit-150, Transit-250, Transit-350, and Transit-350 HD, plus 2017-2020 Lincoln Continental, 2017-2019 Ford Fusion, 2016-2018 Lincoln MKX, and 2015-2017 Ford Expedition.

What This Kit Helps Address

• Fuel seepage around injector sealing points
• Hard starting caused by compromised injector seals
• Rough idle related to injector air or fuel leakage
• Fuel odor from worn upper or lower injector seals
• Service replacement needs during injector removal and reinstallation

Installation Notes and Tips

Inspect injector bores and sealing surfaces before installation, and replace damaged seals rather than reusing worn components. Confirm the injector style and engine application against the vehicle listing before service, especially on Ford F-150 direct injection applications and other upper-and-lower injector configurations. Clean mating surfaces thoroughly so the new seals seat evenly and maintain proper fuel-system sealing.

Quality Assurance

Mahle supplies sealing products used by OEMs and technicians worldwide, and GS33877 is built to OE-standard expectations for fit and sealing performance. This part cross-references Ford BL3Z-9229-B and Motorcraft CM-5209 for the same application.