MPA Electrical NM4057 Brake Master Cylinder

Brake Master Cylinder for GM Front Disc Brake Applications

MPA Electrical NM4057 is a new brake master cylinder built for vehicles with front disc brakes. It is a standard replacement unit with an aluminum body, plastic reservoir, and DOT 3 fluid compatibility for direct hydraulic system service.

Compatible With 2004-2008 Pontiac Grand Prix, 2005 Buick Allure, and 2005 Buick LaCrosse with front disc brakes. This NM4057 master cylinder is engineered to restore brake pedal response and hydraulic pressure consistency in the original braking system.

Key Features

• Brand: MPA Electrical
• Part number: NM4057
• Brake master cylinder for brake hydraulics service
• Aluminum master cylinder construction
• Plastic reservoir included
• 1-inch master cylinder bore diameter
• Two mounting holes with 0.42-inch mounting hole diameter
• DOT 3 brake fluid type
• New condition, standard replacement grade
• Master cylinder cap included

Product Details

MPA Electrical NM4057 is part of the New with front disc brakes product line, focused on OE-style hydraulic brake service for specific GM applications. The unit is tested against OE specifications using proprietary processes and strict protocols, with the goal of delivering consistent braking performance after installation. The aluminum master cylinder and integrated reservoir support a direct replacement approach for vehicles that require a 1-inch bore master cylinder and front disc brake configuration.

This part cross-references GM OE numbers 19209278 and 89047649 for the same application.

Common Brake Issues This Part Can Address

• Low or inconsistent brake pedal feel
• Internal hydraulic leakage in the master cylinder
• Loss of braking pressure at the pedal
• Brake fluid seepage around the master cylinder body
• Hydraulic performance decline in front disc brake systems

Installation Notes and Tips

• Verify vehicle fitment by year, make, model, and front disc brake configuration before installation.
• Bench bleed the master cylinder before connecting brake lines to reduce trapped air in the hydraulic system.
• Use DOT 3 brake fluid only, as specified.
• Mounting hardware, push rod, brake booster, seals, and sensors are not included.
• Inspect brake lines, fittings, and the booster interface for wear or contamination during replacement.

Quality Assurance

MPA Electrical tests each brake master cylinder against OE specifications using controlled procedures and sample-based validation from its OE reference library. NM4057 is a new standard replacement part built for direct hydraulic brake service on the listed Pontiac and Buick applications.