MPA Electrical NM1489 Brake Master Cylinder

Brake Master Cylinder for Front Drum Brake Applications

The MPA Electrical NM1489 brake master cylinder is a standard replacement for classic vehicles with front drum brakes. It is built with a cast iron body, an integral reservoir, and a 1-inch bore to help restore consistent hydraulic brake pressure in the original braking system.

Compatible With 1967-1978 Buick, Cadillac, Oldsmobile, Pontiac, and Jeep applications listed below, this NM1489 master cylinder is a direct-fit service part for restoration and repair work. The MPA Electrical New with front drum brakes product line focuses on OE-style replacement coverage for vehicles that need the correct brake hydraulics configuration.

Key Features

• Part number NM1489 brake master cylinder
• Cast iron master cylinder construction
• 1-inch bore diameter
• Integral reservoir with included cap
• Standard replacement grade
• Uses DOT 3 brake fluid
• Two mounting holes with 0.430-inch mounting hole diameter
• No brake booster, push rod, sensor, or pressure switch included

Detailed Product Description

MPA Electrical NM1489 is engineered as a brake master cylinder replacement for vehicles equipped with front drum brakes. The cast iron housing and integral reservoir support dependable hydraulic operation, while the 1-inch bore size matches the listed applications for proper pedal feel and brake system response. This part cross-references 5458521 and 5463417 for the same application.

Fits 1976-1978 Jeep CJ5, N/A; Fits 1976-1978 Jeep CJ7, N/A; Fits 1974-1978 Jeep J10, N/A; Fits 1974-1976 Jeep Cherokee, N/A; Fits 1974 Jeep J20, N/A; Fits 1967-1972 Buick Skylark, N/A; Fits 1967-1972 Oldsmobile Cutlass, N/A; Fits 1967-1972 Oldsmobile Cutlass Supreme, N/A; Fits 1967-1972 Pontiac GTO, N/A; Fits 1967-1972 Pontiac LeMans, N/A; Fits 1967-1970 Buick LeSabre, N/A; Fits 1967-1970 Buick Riviera, N/A; Fits 1967-1970 Oldsmobile 98, N/A; Fits 1967-1970 Oldsmobile Delta 88, N/A; Fits 1967-1970 Pontiac Bonneville, N/A; Fits 1967-1970 Pontiac Catalina, N/A; Fits 1967-1970 Pontiac Tempest, N/A; Fits 1968-1969 Pontiac Firebird, N/A; Fits 1967-1969 Pontiac Grand Prix, N/A; Fits 1967-1968 Cadillac DeVille, N/A; Fits 1967-1968 Cadillac Eldorado, N/A; Fits 1967-1968 Cadillac Fleetwood, N/A.

What It Helps Address

• Soft or inconsistent brake pedal response
• Loss of hydraulic pressure in the brake system
• Brake fluid leakage from a worn master cylinder
• Brake performance decline on front drum brake vehicles
• Restoration needs for original-style brake hydraulics

Installation Notes and Tips

Verify the vehicle’s front drum brake configuration before installation. Confirm bore size, mounting hole spacing, and reservoir style against the original unit to ensure proper fitment. Bench bleeding is recommended before installation, and DOT 3 brake fluid should be used. Mounting hardware, gasket or seal, push rod, brake booster, sensor, and brake pressure switch are not included.

Quality Assurance

MPA Electrical tests each brake master cylinder against OE specifications using controlled inspection and validation processes based on OE sample references. This helps ensure consistent braking performance after installation and supports reliable service on classic Buick, Cadillac, Oldsmobile, Pontiac, and Jeep brake systems.