Raybestos MC39566 Brake Master Cylinder

Reliable Brake Master Cylinder for Buick, Cadillac, and Oldsmobile

The Raybestos Element3; New Brake Master Cylinder MC39566 is engineered to restore precise brake hydraulics performance in select Buick, Cadillac, and Oldsmobile models. Designed with durable aluminum construction and specific mounting features, this master cylinder ensures consistent braking response for vehicles like the DeVille, Eldorado, and Riviera.

• Constructed from lightweight, corrosion-resistant aluminum
• Two mounting holes with 0.433-inch diameter for secure installation
• 1.125-inch bore size optimized for brake fluid pressure control
• Four ports including M11x1.5 primary and M12x1 secondary port threads
• Compatible with multiple GM luxury and commercial chassis models

Product Line Details: Raybestos Element3; New

The Element3; New line from Raybestos focuses on delivering reliable brake hydraulics components with modern materials and precise engineering. This brake master cylinder is part of that line, offering improved durability and fitment accuracy for classic GM vehicles. The aluminum master cylinder material supports long-term resistance to wear and corrosion, aligning with the Element3; New commitment to quality replacement parts.

Technical Description and Specifications

This brake master cylinder features a 1.125-inch bore size, which is critical for maintaining proper hydraulic pressure in the braking system. The unit includes four ports, with primary and secondary port threads sized M11x1.5 and M12x1 respectively, allowing for secure brake line connections. The two mounting holes, each with a diameter of 0.433 inches, ensure a stable and precise fit on compatible vehicles. The aluminum construction reduces weight while resisting corrosion, making it suitable for long-term use in Buick, Cadillac, and Oldsmobile models such as the Fleetwood, Reatta, and Toronado.

Common Applications and Problem Resolution

• Restores brake fluid pressure in Buick DeVille and Cadillac Eldorado brake systems
• Replaces worn or leaking master cylinders in Oldsmobile Riviera and Seville
• Addresses spongy or unresponsive brake pedal issues in GM commercial chassis
• Eliminates brake fluid leaks caused by damaged ports or seals
• Improves overall brake system reliability and safety

Installation Notes and Tips

Ensure the mounting holes align precisely with the vehicle’s brake booster or firewall. Use the specified 0.433-inch diameter mounting holes for secure attachment. Verify that brake lines match the M11x1.5 primary and M12x1 secondary port threads to avoid leaks. Bleed the brake system thoroughly after installation to remove air and restore proper hydraulic pressure. Consult vehicle-specific service manuals for torque specifications and detailed installation procedures.

Quality Assurance and Warranty

The Raybestos Element3; New MC39566 brake master cylinder is manufactured to meet or exceed OEM standards for fit, form, and function. The aluminum material and precise machining contribute to long service life and consistent braking performance. While specific warranty details are not provided here, Raybestos products typically come with a limited warranty against defects in materials and workmanship. Refer to Raybestos documentation for exact warranty terms.