Dorman M639047 Brake Master Cylinder

Reliable Brake Master Cylinder Replacement for Your Vehicle

The Dorman M639047 brake master cylinder is engineered to restore proper brake hydraulics performance in compatible vehicles. Designed with a durable cast iron construction and precise bore diameter, this master cylinder ensures consistent brake fluid pressure for safe stopping power.

• Master cylinder bore diameter: 0.875 inches for accurate hydraulic control
• Constructed from cast iron for strength and durability
• Includes four outlets to support complex brake line configurations
• Rearward outlet size: (2) M12x1.0 threads
• Secondary outlet thread diameter: (2) M10x1.0 with 1.0 thread pitch
• Package contains the master cylinder only; mounting hardware and reservoir are not included

Detailed Product Features and Specifications

The Dorman M639047 brake master cylinder is designed to meet the demands of vehicles requiring a 0.875-inch bore diameter master cylinder. Its cast iron material provides resistance to wear and corrosion, ensuring long-term reliability under typical braking system conditions. The unit features four outlets, including two rearward outlets with M12x1.0 thread size and two secondary outlets with M10x1.0 thread diameter, allowing compatibility with various brake line setups. Note that this product does not include a reservoir or sensor, and mounting hardware must be sourced separately.

Common Applications and Problem Resolution

This brake master cylinder is suitable for vehicles that require a robust and precise hydraulic component to maintain brake system integrity. It addresses several brake system issues, including:

• Spongy or unresponsive brake pedal feel due to internal cylinder wear
• Brake fluid leaks from a failing master cylinder
• Uneven brake pressure distribution causing pulling or reduced stopping power
• Brake warning light activation related to master cylinder malfunction
• Loss of hydraulic pressure affecting overall brake performance

Installation Notes and Tips

When installing the Dorman M639047 master cylinder, ensure the brake system is properly bled to remove air pockets and restore hydraulic pressure. Since mounting hardware and reservoir are not included, verify compatibility with existing components or acquire necessary parts before installation. Use thread sealant or appropriate fittings for the M12x1.0 and M10x1.0 outlets to prevent leaks. Follow vehicle-specific service manual instructions for torque specifications and safety precautions.

Quality Assurance and Warranty Information

Dorman manufactures the M639047 brake master cylinder to meet or exceed OEM standards for fit, form, and function. The cast iron construction undergoes rigorous quality control to ensure durability and performance. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in material and workmanship. Consult product documentation or the manufacturer for exact warranty terms.