Dorman M630078 Brake Master Cylinder

Reliable Brake Master Cylinder for Volkswagen Models

The Dorman M630078 brake master cylinder is engineered to provide consistent hydraulic pressure for Volkswagen Cabriolet, Golf, and Jetta vehicles. Designed with durable cast iron construction, this master cylinder ensures dependable braking performance tailored to specific Volkswagen brake systems.

Key Features of the Dorman M630078 Brake Master Cylinder

• Master cylinder bore diameter: 20 mm for precise hydraulic control
• Constructed from cast iron for enhanced durability and strength
• Includes four outlets to support complex brake line configurations
• Secondary outlet thread diameter of 10 mm with a 1.0 thread pitch
• Rearward outlet size specified as M10 x 1.0 for exact fitment
• Package contains the master cylinder only; mounting hardware and reservoir are not included
• Compatible with Volkswagen Cabriolet, Golf, and Jetta models

Detailed Product Description

The Dorman M630078 brake master cylinder is a critical component in the brake hydraulics system of Volkswagen Cabriolet, Golf, and Jetta vehicles. Its 20 mm bore diameter allows for accurate pressure modulation, essential for safe and responsive braking. Manufactured from cast iron, this master cylinder offers resistance to wear and corrosion, extending the service life of the brake system. The unit features four outlets, including a rearward outlet sized M10 x 1.0, accommodating the specific brake line configurations found in these Volkswagen models. Note that this part does not include a reservoir or mounting hardware, so those components must be sourced separately if needed.

Common Applications and Issues Addressed

• Restores proper hydraulic pressure in Volkswagen Cabriolet, Golf, and Jetta brake systems
• Replaces worn or leaking master cylinders causing brake fluid loss
• Eliminates spongy or unresponsive brake pedal feel
• Resolves brake system failure due to internal cylinder wear or damage
• Supports brake system maintenance and rebuild projects on compatible Volkswagen models

Installation Notes and Tips

• Ensure compatibility with Volkswagen Cabriolet, Golf, and Jetta before installation
• Bleed the brake system thoroughly after installation to remove air pockets
• Use appropriate brake fluid as specified by the vehicle manufacturer
• Inspect and replace mounting hardware and reservoir if necessary, as these are not included
• Follow vehicle-specific service manual instructions for torque specifications and procedures

Quality Assurance and Warranty Information

Dorman manufactures the M630078 brake master cylinder to meet or exceed OEM standards for fit and function. The cast iron construction provides durability under normal operating conditions. While mounting hardware and reservoir are not included, the master cylinder itself is backed by Dorman's quality control processes. Please refer to Dorman's official warranty policy for coverage details.