Dorman M39704 Brake Master Cylinder

Reliable Brake Master Cylinder for Mercedes-Benz Models

The Dorman M39704 Brake Master Cylinder is engineered to restore proper brake hydraulics for select Mercedes-Benz vehicles. Designed with precision, this aluminum master cylinder ensures consistent brake fluid pressure for safe and effective braking performance.

• Compatible with Mercedes-Benz 300SD, 300SDL, 300SE, 300SEL, 300SL, 350SD, 350SDL, 400E, 420SEL, 500E, 500SEC, 500SL, 560SEC, 560SEL, 560SL, E420, E500, S320, S350, SL320, and SL500 models
• Constructed from durable aluminum for corrosion resistance and longevity
• Dual bore diameters of 0.75 and 1 inch for precise hydraulic control
• Includes three outlets with a rearward outlet size of M10 x 1.0 and a thread pitch of 1.0
• Does not include mounting hardware or reservoir, sold as master cylinder only

Technical Details and Specifications

The Dorman M39704 brake master cylinder features a dual bore design with bore diameters of 0.75 and 1 inch, allowing for balanced hydraulic pressure distribution. Manufactured from aluminum, this master cylinder offers enhanced resistance to wear and corrosion compared to traditional cast iron units. It includes three outlets, with the secondary outlet thread diameter measuring 10 mm and a rearward outlet size of M10 x 1.0, ensuring compatibility with the brake lines on specified Mercedes-Benz models. The thread pitch is 1.0, matching OEM specifications for secure fitting. Note that this unit does not come with a reservoir or mounting hardware, so these components must be sourced separately if needed.

Common Applications and Problem Resolution

• Restores brake fluid pressure in Mercedes-Benz 300SD and 500SL brake systems
• Addresses issues related to brake pedal sinking or sponginess
• Replaces master cylinders with internal leaks or worn seals
• Solves inconsistent braking response in models like the 420SEL and 560SEL
• Eliminates brake fluid contamination caused by corroded or damaged master cylinders

Installation Notes and Tips

• Ensure brake system is fully depressurized before removal
• Bleed the brake system thoroughly after installation to remove air pockets
• Verify compatibility with your specific Mercedes-Benz model and year prior to installation
• Use OEM or compatible brake fluid to maintain system integrity
• Inspect brake lines and fittings for wear or damage during installation

Quality Assurance and Warranty Information

Dorman manufactures the M39704 brake master cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction provides durability and corrosion resistance for extended service life. While mounting hardware and reservoir are not included, the master cylinder is designed for direct replacement on compatible Mercedes-Benz models. Warranty coverage details should be confirmed at the point of purchase, as they may vary.