MPA Electrical B3665 Power Brake Booster

Vacuum Brake Booster for BMW X5 and X6

MPA Electrical B3665 is a remanufactured vacuum power brake booster built for BMW X5 and BMW X6 applications. It is engineered to deliver strong braking assist with reduced pedal effort, using treated replacement components and 100% end-of-line testing for consistent vacuum sealing and pressure transfer.

This reman vac pwr brake booster w/o master cyl is a direct-fit service part for BMW X5 and BMW X6 owners replacing a worn or leaking booster. Part number B3665 is also cross-referenced to OE numbers 34336772929 and 34336791410 for the same application.

Key Features

• Remanufactured vacuum power brake booster
• Standard replacement brake service grade
• Metal housing construction
• 10.71 in. / 272.03 mm diaphragm diameter
• Brake pedal rod extension included
• 2 mounting studs with 8 x 1.25 mm master cylinder stud thread size
• Master cylinder not included
• Gasket or seal not included
• Mounting bracket not included
• Front seal not included

Product Details

MPA Electrical’s reman vac pwr brake booster line is built for dependable vacuum-assisted braking in everyday driving conditions. B3665 uses a vacuum booster design with a metal housing and a large diaphragm to help maintain consistent brake assist and pedal response. Each unit is tested at the end of the production process to verify performance before release.

Compatible With 2007-2013 BMW X5 and 2008-2019 BMW X6, this booster is a practical replacement when the original unit shows signs of vacuum loss, hard pedal feel, or inconsistent brake assist. Part number B3665 is commonly searched as a BMW X5 brake booster replacement and BMW X6 vacuum brake booster remanufactured unit.

Common Problems This Part Can Address

• Hard brake pedal feel
• Reduced brake assist during stopping
• Vacuum leak at the booster assembly
• Brake pedal effort that has increased over time
• Brake booster wear on high-mileage BMW X5 or BMW X6 vehicles

Installation Notes and Tips

Verify the master cylinder is transferred or replaced separately, since it is not included with this booster. Confirm the 2-stud mounting pattern, 8 x 1.25 mm master cylinder stud thread size, and pedal rod extension before installation. Inspect vacuum supply lines, check valves, and related brake components for wear before completing the repair.

For best results, compare the original booster to B3665 before removal and confirm vehicle application by year, make, and model. This helps ensure proper fitment on BMW X5 and BMW X6 brake system service jobs.

Quality Assurance

MPA Electrical remanufactures this booster with replacement and specially treated components to support vacuum sealing and pressure transfer. Each unit undergoes 100% end-of-line testing using proprietary equipment to verify function before it leaves the factory.