Bosch 66821 Direct Injection High Pressure Fuel Pump

Bosch GDI High Pressure Pump for Mercedes-Benz

The Bosch GDI High Pressure Pump, part number 66821, is a direct injection fuel pump for select Mercedes-Benz applications. It is an electric, internal high pressure pump built for vehicles that rely on precise fuel delivery under direct injection operating conditions.

Key Features

• Bosch GDI High Pressure Pump (New) for direct injection fuel systems
• Electric, internal fuel pump design
• New unit with one outlet
• No gasket included
• No mounting hardware included
• Cross-references Bosch 2760700601 for the same application

Product Details

Bosch part number 66821 is part of the Bosch GDI High Pressure Pump product line, which brings OE-level fuel system engineering to the aftermarket. Bosch manufactures these pumps on the same production lines used for original equipment components and tests them to the same quality standards, helping maintain consistent fuel pressure and dependable operation in direct injection systems. This pump is a direct fit for select Mercedes-Benz models, including the Mercedes-Benz E350, C350, ML350, and GLK350, as well as other listed applications.

Compatible With 2016-2018 Mercedes-Benz GLE350, N/A; 2012-2016 Mercedes-Benz E350, N/A; 2012-2016 Mercedes-Benz SLK350, N/A; 2012-2015 Mercedes-Benz C350, N/A; 2013-2015 Mercedes-Benz E400, N/A; 2013-2015 Mercedes-Benz GLK350, N/A; 2012-2015 Mercedes-Benz ML350, N/A; 2013-2014 Mercedes-Benz C300, N/A; and 2012-2013 Mercedes-Benz R350, N/A.

Common Issues This Pump Can Address

• Low fuel pressure in a direct injection system
• Hard starting caused by inadequate high-pressure fuel delivery
• Engine hesitation or stumble under load
• Fuel delivery faults related to a worn high pressure pump
• Driveability problems tied to inconsistent injector supply pressure

Installation Notes and Tips

Verify engine code and fuel system configuration before installation. Because this is an internal electric high pressure pump, inspect related fuel system components, seals, and lines for wear or contamination during service. Follow factory service procedures for depressurizing the fuel system and priming the system after installation. Confirm fitment against the vehicle application list for the Mercedes-Benz E350, C350, ML350, and related models before ordering.

Quality Assurance

Bosch builds this pump using the same manufacturing and testing standards applied to its original equipment fuel pumps. That OE-focused process supports consistent performance and long service life in direct injection applications.