MPA Electrical B1057 Power Brake Booster

Vacuum Brake Booster for GM S-Series Applications

MPA Electrical B1057 is a remanufactured vacuum power brake booster built for GM S-Series trucks and SUVs that need consistent brake assist and a firm pedal feel. It is a standard replacement unit with a dual diaphragm design, metal housing, and a 10.83 in. (275.08 mm) diaphragm diameter.

Compatible With 1988-1994 Chevrolet S10 Blazer, 1992-1994 GMC Jimmy, 1988-1993 Chevrolet S10, 1991-1993 GMC Sonoma, 1991-1993 Oldsmobile Bravada, 1988-1991 GMC S15 Jimmy, and 1988-1990 GMC S15. Part number B1057 is also referenced for OE-style replacement applications under 18014925 and 18021970.

Key Features

• Remanufactured vacuum power brake booster
• Dual diaphragm construction for brake assist delivery
• Metal housing for durable mounting support
• Standard replacement brake service grade
• Master cylinder stud thread size: 10 x 1.5
• Two mounting studs
• Master cylinder not included
• Brake pedal rod extension not included

Product Details

MPA Electrical’s Reman Vac Pwr Brake Booster w/o Master Cyl line focuses on restored braking performance for vehicles that rely on vacuum assist. This B1057 booster is remanufactured with new replacement and specially treated components to help maintain vacuum sealing, pressure transfer, and pedal response. Each unit is end-of-line tested to verify function before release.

This part is a direct-fit style vacuum booster for Chevrolet S10 Blazer and S10, GMC Jimmy, Sonoma, S15 Jimmy, and S15, as well as Oldsmobile Bravada models listed above. Part number B1057 should be matched to the vehicle’s original booster configuration, including the 10 x 1.5 master cylinder stud thread size and two-stud mounting layout.

What It Helps Address

• Hard brake pedal feel
• Reduced brake assist from a worn vacuum booster
• Loss of vacuum seal at the booster housing
• Inconsistent pedal response during braking
• Brake system performance issues tied to booster wear

Installation Notes

Verify the existing booster style, diaphragm size, mounting stud layout, and master cylinder stud thread before installation. This unit does not include the master cylinder, gasket or seal, front seal, mounting bracket, or brake pedal rod extension. Confirm all brake and vacuum connections are clean and in good condition before reassembly.

Quality Assurance

MPA Electrical remanufactures this booster with treated replacement components and tests every unit at the end of the production line using proprietary equipment to confirm braking assist performance and vacuum integrity.