Dorman M639046 Brake Master Cylinder

Overview of the Dorman Brake Master Cylinder M639046

The Dorman Brake Master Cylinder M639046 is a cast iron hydraulic component designed to deliver reliable braking performance. Engineered for vehicles requiring a 0.8125-inch bore diameter, this master cylinder supports brake systems with four outlets, ensuring consistent fluid distribution.

• Cast iron construction for durability and strength
• Master cylinder bore diameter of 0.8125 inches
• Four outlets for efficient brake fluid flow
• Rearward outlet size: two M12x1.0 threaded ports
• Secondary outlet thread diameter: two M10x1.0 ports
• Includes master cylinder only; no reservoir or mounting hardware included

Detailed Product Description

The Dorman M639046 brake master cylinder is crafted from cast iron, providing a robust and corrosion-resistant solution for brake hydraulics. Its 0.8125-inch bore diameter is suitable for specific vehicle brake systems that require precise fluid pressure control. The unit features four outlets, with two rearward outlets sized at M12x1.0 and two secondary outlets at M10x1.0, both with a thread pitch of 1.0, facilitating secure and leak-free connections to brake lines. This master cylinder does not include a reservoir or sensor, making it ideal for applications where these components are serviced separately or already installed.

Compatible Vehicles and Applications

This brake master cylinder is compatible with various vehicle makes and models that specify a 0.8125-inch bore diameter and the described outlet configurations. It is commonly used in automotive brake systems requiring a four-outlet master cylinder with cast iron construction. For example, it fits certain models of Ford, Chevrolet, and Dodge vehicles that utilize similar brake hydraulic specifications. Always verify fitment with your vehicle’s service manual or parts catalog using the part number M639046.

Common Issues Addressed by the Dorman M639046

• Brake pedal sinking or sponginess due to master cylinder wear
• Brake fluid leaks from worn or damaged master cylinder seals
• Inconsistent brake pressure affecting stopping performance
• Failure of brake hydraulics causing reduced braking efficiency
• Replacement of a faulty or corroded master cylinder in cast iron brake systems

Installation Notes and Tips

• Ensure the brake system is properly bled after installation to remove air
• Verify thread sizes (M12x1.0 and M10x1.0) match existing brake lines
• Use appropriate brake fluid as specified by the vehicle manufacturer
• Inspect related brake components such as the reservoir and sensors, as these are not included
• Professional installation is recommended to maintain brake system integrity

Quality Assurance and Warranty

Dorman manufactures the M639046 brake master cylinder to meet or exceed OEM standards for fit, form, and function. The cast iron material ensures long-lasting durability under typical operating conditions. While specific warranty details vary, Dorman generally offers a limited warranty covering defects in material and workmanship. Consult the product packaging or Dorman’s official resources for exact warranty terms.