MPA Electrical B1157 Power Brake Booster

Reman Vacuum Brake Booster for Cobalt and G5

MPA Electrical B1157 is a remanufactured vacuum power brake booster built for direct replacement service on select Chevrolet and Pontiac compact cars. It is engineered for maximum braking assist with low pedal effort, with new replacement and specially treated components used to support vacuum sealing and pressure transfer.

This reman vac pwr brake booster w/o master cyl is a standard replacement part for drivers servicing brake assist concerns on the Chevrolet Cobalt, Pontiac G5, Pontiac G4, and Pontiac Pursuit. The B1157 is a vacuum booster with a metal housing, 224.03 mm (8.82 in.) diaphragm diameter, 8 x 1.25 mm master cylinder stud thread size, and two mounting studs.

Key Features

• Remanufactured vacuum power brake booster
• Standard replacement brake service grade
• Metal housing for OE-style fitment
• 224.03 mm / 8.82 in. diaphragm diameter
• 8 x 1.25 mm master cylinder stud thread size
• Two mounting studs
• Master cylinder not included
• Brake pedal rod extension not included
• Mounting bracket, gasket, seal, and front seal not included

Product Details

MPA Electrical B1157 is built as a reman vacuum brake booster for vehicles that rely on vacuum-assisted braking. The unit is tested at the end of the production line with proprietary equipment to verify performance before release. This part cross-references OE numbers 15261541 and 22715702 for the same application. Search terms such as 2005 Chevrolet Cobalt brake booster replacement, 2007 Pontiac G5 vacuum brake booster, and reman power brake booster without master cylinder help identify the correct application.

What It Helps Address

• Hard brake pedal feel
• Reduced brake assist from a failing vacuum booster
• Brake pedal effort that increases during stops
• Loss of consistent vacuum pressure transfer
• Brake system service on a worn reman booster assembly

Installation Notes

Verify the master cylinder stud thread size, mounting stud layout, and booster diameter before installation. This unit does not include the master cylinder, pedal rod extension, gasket, seal, or mounting bracket, so reuse or source the correct related components as needed. Confirm brake system condition and vacuum supply before returning the vehicle to service.

Quality Assurance

MPA Electrical reman brake boosters are assembled with replacement and specially treated components to support vacuum sealing and reliable pressure transfer. Each unit is subjected to 100% end-of-line testing using proprietary test equipment for consistent output.

Compatible With: 2005-2008 Chevrolet Cobalt, 2007-2008 Pontiac G5, 2005-2006 Pontiac G4, and 2005-2006 Pontiac Pursuit.