Dorman M630409 Brake Master Cylinder

Brake Master Cylinder for Honda Prelude

This Dorman brake master cylinder is built for 1990-1991 Honda Prelude applications with 15/16-inch bore size drum brakes. It uses new aluminum construction, includes a reservoir and sensor, and is engineered to match the original master cylinder’s design, function, and performance.

• Direct replacement brake master cylinder for select Honda Prelude models
• 0.938-inch bore diameter for the specified brake setup
• Aluminum master cylinder body for durable service
• Reservoir included for a complete hydraulic assembly
• Sensor included
• Two outlet design with M12 x 1.0 rearward outlet and 10 mm secondary outlet thread
• Part number M630409 for easy identification

Detailed Product Overview

Dorman M630409 is a brake master cylinder replacement for 1990-1991 Honda Prelude vehicles equipped with 15/16-inch bore size drum brakes. It is precision-engineered to follow the original unit’s layout and hydraulic function, helping restore proper brake system operation with new, high-quality materials. The aluminum construction, integrated reservoir, and included sensor support a clean OE-style replacement for the Honda Prelude brake hydraulics system.

This part cross-references Centric Parts 130.40018 for the same application.

What This Part Helps Address

• Brake pedal travel that feels excessive or inconsistent
• Loss of hydraulic pressure in the brake system
• External leakage at the master cylinder body or outlets
• Warning light concerns related to the brake system sensor
• Restoration needs for a worn Honda Prelude master cylinder

Installation Notes and Tips

Verify bore size, outlet thread sizes, and vehicle brake configuration before installation. This Dorman M630409 master cylinder is supplied without mounting hardware, so reuse or source the required fasteners as needed. Bench bleeding the master cylinder before installation helps reduce trapped air and supports proper brake pedal feel after the system is bled.

Quality Assurance

Dorman designs this brake master cylinder as a direct-fit replacement for specific Honda Prelude applications, using new materials and OE-style engineering to match the original part’s function and performance. Confirm fitment for 1990-1991 Honda Prelude, and verify the 15/16-inch bore drum brake application before ordering.