MPA Electrical NM1870 Brake Master Cylinder

Brake Master Cylinder for GM Full-Size Applications

Restore consistent brake pedal response with this MPA Electrical brake master cylinder, part number NM1870. It is a standard replacement unit for front disc brake applications on a wide range of Cadillac, Chevrolet, Buick, Oldsmobile, and Pontiac models from the 1980s and early 1990s.

Built with an aluminum master cylinder body, integrated reservoir, and included cap, NM1870 is engineered for direct hydraulic replacement where original braking performance has declined. It uses DOT 3 brake fluid and a 1.575-inch bore diameter for the specified applications.

Key Features

• MPA Electrical NM1870 brake master cylinder
• Standard replacement grade for brake hydraulic service
• Aluminum master cylinder construction
• 1.575-inch bore diameter
• Reservoir included; master cylinder cap included
• Uses DOT 3 brake fluid
• 2 mounting holes with 0.423-inch mounting hole diameter
• New with front disc brakes applications

Detailed Description

MPA Electrical NM1870 is a brake master cylinder for front disc brake vehicles that need a direct hydraulic replacement. It is listed for 1981-1993 Chevrolet Commercial Chassis, 1988-1992 Cadillac Brougham, 1981-1992 Cadillac Commercial Chassis, 1981-1990 Buick LeSabre, 1981-1990 Chevrolet Caprice, 1981-1990 Oldsmobile Custom Cruiser, 1987-1989 Pontiac Safari, 1981-1986 Cadillac Fleetwood, 1981-1986 Pontiac Parisienne, 1981-1985 Chevrolet Impala, 1981-1985 Oldsmobile Delta 88, 1981-1984 Cadillac DeVille, 1981-1984 Oldsmobile 98, 1981 Chevrolet Bel Air, 1981 Chevrolet Camaro, 1981 Pontiac Bonneville, 1981 Pontiac Catalina, 1981 Pontiac Firebird, and 1980-1981 Pontiac Laurentian.

MPA Electrical uses OE sample data and testing protocols to verify the unit against original specifications before release. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Fix

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

Installation Notes and Tips

Confirm the vehicle is listed for the front disc brake application before installation. Verify bore size, mounting hole spacing, and reservoir configuration against the original unit. Bench bleeding the master cylinder before final installation helps remove trapped air from the hydraulic circuit and supports proper pedal feel after service.

Quality Assurance

Each MPA Electrical master cylinder is tested against OE specifications using controlled inspection and validation processes based on an OE sample library. That process helps ensure consistent hydraulic performance out of the box for the listed Cadillac, Chevrolet, Buick, Oldsmobile, and Pontiac applications.