Dorman M39952 Brake Master Cylinder

Reliable Brake Master Cylinder for Buick, Chevrolet, and Oldsmobile

The Dorman M39952 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Buick, Chevrolet, and Oldsmobile models. Designed with an aluminum body and an included reservoir, this master cylinder ensures consistent brake fluid delivery for safe and effective braking performance.

Key Features of the Dorman M39952 Brake Master Cylinder

• Constructed from durable aluminum for corrosion resistance and longevity
• Includes an integrated reservoir for brake fluid storage
• Dual outlet design with two outlets for efficient brake line connection
• Master cylinder bore diameter measures 40 mm & 1-1/8 inch for precise hydraulic pressure
• Rearward outlet size: M11 x 1.5 thread specification
• Secondary outlet thread diameter: M12 x 1.0 with 1.0 thread pitch
• Package contains the master cylinder unit only; mounting hardware not included

Detailed Description of the Dorman M39952 Brake Master Cylinder

This brake master cylinder is specifically designed for compatibility with Buick Caprice, Chevrolet Custom Cruiser, and Oldsmobile Roadmaster models. The aluminum construction provides a lightweight yet robust component that resists rust and wear over time. The included reservoir simplifies brake fluid management, while the dual outlet configuration supports proper brake line connections. The precise bore diameter of 40 mm & 1-1/8 inch ensures consistent hydraulic pressure for reliable braking response. Thread specifications for the rearward and secondary outlets are engineered to match OEM standards, facilitating a secure fit with existing brake lines.

Common Brake Issues Addressed by This Master Cylinder

• Spongy or unresponsive brake pedal due to master cylinder wear
• Brake fluid leaks from a damaged or corroded master cylinder
• Inconsistent brake pressure affecting stopping performance
• Brake warning light activation related to master cylinder failure
• Brake pedal sinking or failure to maintain pressure under load

Installation Notes and Tips

• Ensure brake system is fully depressurized before removal
• Bleed the brake system thoroughly after installation to remove air
• Verify thread sizes (M11 x 1.5 and M12 x 1.0) for proper brake line connection
• Use compatible brake fluid as specified by vehicle manufacturer
• Check for leaks and proper pedal feel before driving

Quality Assurance and Warranty Information

Dorman manufactures this brake master cylinder to meet or exceed OEM specifications for fit, form, and function. While specific warranty details are not provided here, Dorman products typically come with a limited warranty covering defects in materials and workmanship. Refer to Dorman’s official documentation for complete warranty terms.