MPA Electrical NM4021 Brake Master Cylinder

Brake Master Cylinder for Buick and Pontiac

Restore consistent brake pedal response with this new brake master cylinder from MPA Electrical. Built as a standard replacement for vehicles with front disc brakes, NM4021 is engineered for dependable hydraulic performance in daily driving conditions.

Compatible with 2002-2007 Buick Rendezvous and 2001-2005 Pontiac Aztek, this brake master cylinder is a direct-fit service part for common brake hydraulic repairs. The NM4021 part number is also useful when cross-referencing OE-style replacement needs for these applications.

Key Features

• Brake master cylinder for brake hydraulic service
• Standard replacement grade
• 1-inch master cylinder bore diameter
• Aluminum master cylinder body with plastic reservoir
• Reservoir included with cap included
• Uses DOT 3 brake fluid
• 2 mounting holes with 0.425-inch mounting hole diameter
• New condition
• MPA Electrical NM4021

Product Details

MPA Electrical brake master cylinders are built to restore braking performance using OE sample references and controlled testing against original specifications. This unit is configured with a 1-inch bore, aluminum construction, and an integrated plastic reservoir to support stable hydraulic pressure for front disc brake applications. NM4021 is a practical replacement choice for Buick Rendezvous and Pontiac Aztek models that need renewed master cylinder function.

This part cross-references OE numbers 18045967 and 18060786 for the same application.

Common Problems This Part Can Address

• Low or inconsistent brake pedal feel
• Internal master cylinder leakage
• Brake fluid loss at the hydraulic unit
• Reduced braking response after master cylinder wear
• Brake warning symptoms tied to hydraulic pressure loss

Installation Notes and Tips

• Bench bleed the master cylinder before installation to reduce trapped air in the hydraulic system.
• Inspect brake lines, fittings, and the booster interface before installation.
• Use fresh DOT 3 brake fluid and bleed the system thoroughly after installation.
• Mounting hardware, gasket or seal, push rod, brake booster, and brake pressure switch are not included.

Quality Assurance

MPA Electrical tests each master cylinder against OE specifications using proprietary processes and strict protocols to help ensure consistent braking performance out of the box. This NM4021 brake master cylinder is a new standard replacement part for Buick Rendezvous and Pontiac Aztek front disc brake applications.