Dorman M39678 Brake Master Cylinder

Reliable Dorman Brake Master Cylinder for Precise Brake Control

The Dorman M39678 brake master cylinder is engineered to deliver consistent hydraulic pressure for your vehicle's braking system. Designed with a 22mm bore diameter and durable cast iron construction, this master cylinder ensures reliable performance for various automotive applications.

• Cast iron master cylinder material for durability
• 22mm master cylinder bore diameter for precise hydraulic control
• Four outlet ports with M10 x 1.0 rearward outlet thread size
• Includes master cylinder only; mounting hardware and reservoir not included
• Thread pitch of 1.0 for secure fitting

Technical Details and Construction

The Dorman M39678 brake master cylinder features a robust cast iron body designed to withstand the demands of brake hydraulics. Its 22mm bore diameter is optimized for effective pressure generation, while the four outlet ports allow for proper fluid distribution to the brake lines. The rearward outlet size is M10 x 1.0 with a thread pitch of 1.0, ensuring compatibility with standard brake line fittings. This part does not include a reservoir or mounting hardware, so those components must be sourced separately.

Compatible Vehicles and Applications

This brake master cylinder is suitable for replacement in vehicles requiring a 22mm bore diameter and cast iron construction. It is commonly used in various makes and models that specify a master cylinder with four outlets and M10 x 1.0 rearward outlet threads. For exact fitment, verify your vehicle’s OEM specifications against the Dorman M39678 part number.

Common Brake System Issues Addressed

• Brake pedal sinking or sponginess 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 hydraulic failure
• Replacement during brake system overhaul or upgrade

Installation Notes and Tips

When installing the Dorman M39678 brake master cylinder, ensure the brake system is properly bled to remove air and maintain hydraulic integrity. Since mounting hardware and reservoir are not included, use OEM or compatible components for secure installation. Verify thread pitch and outlet sizes to match your vehicle’s brake lines. Professional installation is recommended to maintain brake system safety and performance.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards, providing reliable performance and durability. While specific warranty details for part number M39678 should be confirmed at the time of purchase, Dorman typically offers limited warranties covering defects in material and workmanship.