MPA Electrical M2596 Brake Master Cylinder

Brake Master Cylinder for GM Front Disc Applications

MPA Electrical M2596 is a remanufactured brake master cylinder built for select GM vehicles with front disc brakes. It is a standard replacement unit with a 1-inch bore and cast iron construction, made to restore consistent hydraulic brake performance after wear, leakage, or internal bypass.

This reman with front disc brakes application is engineered and tested against OE specifications using MPA Electrical’s OE sample library and proprietary inspection processes. The result is a brake master cylinder that delivers dependable pedal response for Buick LeSabre, Buick Park Avenue, Cadillac DeVille, Oldsmobile 88, Oldsmobile Delta 88, and Pontiac Bonneville applications.

Key Features

• Remanufactured brake master cylinder for standard replacement service
• 1-inch master cylinder bore diameter
• Cast iron master cylinder body
• Two mounting holes with 0.413-inch mounting hole diameter
• No reservoir, cap, booster, push rod, seal, sensor, or pressure switch included
• Fits front disc brake configurations listed in the vehicle application data
• Cross-reference part numbers: 25558388, 25605860

Detailed Description

MPA Electrical M2596 is a brake master cylinder designed for vehicles that require a remanufactured OE-style hydraulic replacement. The 1-inch bore supports proper brake fluid pressure generation, while the cast iron housing provides the durability expected in a direct-fit brake hydraulic component. This part number is listed for 1990-1993 Buick LeSabre, 1991-1993 Buick Park Avenue, 1991-1993 Cadillac DeVille, 1992-1993 Oldsmobile 88, 1991-1993 Pontiac Bonneville, and 1991 Oldsmobile Delta 88 with front disc brakes. If you are replacing a worn master cylinder on a Buick LeSabre or Cadillac DeVille, M2596 is built for that exact service path.

What It Helps Fix

• Low or inconsistent brake pedal feel
• Internal fluid bypass in the master cylinder
• External brake fluid leakage at the hydraulic unit
• Uneven or delayed brake pressure delivery
• Brake warning symptoms tied to master cylinder wear

Installation Notes and Tips

Before installation, verify the vehicle’s front disc brake configuration and confirm the mounting pattern matches the existing unit. Transfer or source any required components separately, since the reservoir, cap, booster, push rod, seals, and mounting hardware are not included. Bench bleeding the master cylinder before installation helps remove trapped air and supports proper pedal feel after the system is reassembled.

Quality Assurance

MPA Electrical remanufactures this master cylinder using OE sample references and testing protocols aligned to OE specifications. Each unit is inspected to support consistent braking performance out of the box for the listed Buick, Cadillac, Oldsmobile, and Pontiac applications.