MPA Electrical B3781 Power Brake Booster

Remanufactured Vacuum Brake Booster

MPA Electrical B3781 is a remanufactured vacuum power brake booster built for standard replacement service. It is engineered to deliver strong braking assist with low pedal effort, using a 10.56-inch diaphragm, a metal housing, and a vacuum booster design for consistent pressure transfer.

This MPA Electrical brake booster line is built for drivers who need a direct replacement unit that restores pedal feel and braking response. The B3781 is supplied without a master cylinder, and it uses 2 mounting studs with an 8 x 1.25 mm master cylinder stud thread size.

Key Features

• Part number B3781 remanufactured vacuum power brake booster
• Standard replacement brake service grade
• 10.56-inch diaphragm diameter for braking assist
• Metal housing construction
• 2 mounting studs
• Master cylinder not included
• Brake pedal rod extension not included
• Gasket or seal not included
• Front seal not included
• Mounting bracket not included
• 8 x 1.25 mm master cylinder stud thread size

Detailed Description

MPA Electrical B3781 is a reman vac power brake booster designed for vehicles that use a vacuum-assisted braking system. The remanufactured construction combines new replacement and specially treated components to help maintain vacuum seal integrity, pressure transfer, and overall braking performance. Each unit is end-of-line tested with proprietary equipment before release.

For shoppers searching for a reman vacuum brake booster for Honda Civic, Acura, or other vehicle-specific brake repair needs, B3781 provides a direct replacement format focused on restoring pedal assist and brake response. This part cross-references Monroe Shocks & Struts (e.g., 172286) for the same application.

Common Repair Symptoms

• Hard brake pedal feel
• Reduced braking assist from the vacuum booster
• Longer stopping distance caused by poor pedal response
• Vacuum leak symptoms around the brake booster
• Brake pedal effort that feels higher than normal

Installation Notes and Tips

Verify the master cylinder stud thread size, mounting stud layout, and booster depth before installation. Because the master cylinder is not included, transfer or replace the master cylinder separately as needed. Confirm vacuum hose condition, pedal linkage alignment, and firewall fitment during brake system service. Fits only the vehicle applications listed in the catalog data for this part number.

Quality Assurance

MPA Electrical subjects each brake booster to 100% end-of-line testing using proprietary test equipment. The remanufacturing process uses new replacement and specially treated components to support vacuum sealing and pressure transfer consistency.