Dorman M39958 Brake Master Cylinder

Reliable Brake Master Cylinder for Ford and Mercury Vehicles

The Dorman M39958 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Ford and Mercury models. Designed with precision, this master cylinder ensures consistent brake fluid pressure for safe and effective braking performance.

• Master cylinder bore diameter: 1 inch
• Constructed from durable aluminum material
• Includes reservoir and sensor for integrated functionality
• Equipped with four outlets for comprehensive brake line connections
• Rearward outlet sizes: M10 x 1.0 and M16 x 1.5
• Secondary outlet thread diameters: M12 x 1.0 and M18 x 1.5
• Package contains the master cylinder only; mounting hardware not included

Product Details and Specifications

The Dorman M39958 master cylinder is crafted from aluminum, providing a lightweight yet robust component that resists corrosion and wear. Its 1-inch bore diameter is designed to match the hydraulic requirements of Ford and Mercury vehicles such as the Cougar, Sable, Taurus, and Thunderbird. The included reservoir and sensor facilitate accurate fluid level monitoring and brake system feedback. With four outlets, this master cylinder supports multiple brake line connections, featuring rearward outlet sizes of M10 x 1.0 and M16 x 1.5, as well as secondary outlet thread diameters of M12 x 1.0 and M18 x 1.5, ensuring compatibility with the vehicle’s brake hydraulics system.

Compatible Vehicles and Applications

This brake master cylinder is compatible with the following vehicles:

• Ford Cougar
• Ford Sable
• Ford Taurus
• Mercury Cougar
• Mercury Sable
• Mercury Taurus
• Mercury Thunderbird

Common Issues Addressed by This Master Cylinder

• Brake pedal sinking or sponginess due to internal leaks
• Brake fluid leaks around the master cylinder area
• Inconsistent brake pressure affecting stopping performance
• Warning lights triggered by faulty brake fluid sensors
• Brake system failure caused by worn or damaged master cylinder components

Installation Notes and Tips

Installation of the Dorman M39958 master cylinder requires careful attention to brake line connections and proper bleeding of the brake system to remove air. Since mounting hardware is not included, retain or source compatible fasteners for secure installation. Verify outlet thread sizes (M10 x 1.0, M16 x 1.5, M12 x 1.0, M18 x 1.5) to ensure correct brake line fittings. It is recommended to consult the vehicle’s service manual for torque specifications and installation procedures.

Quality Assurance and Warranty

Dorman manufactures this brake master cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction offers durability and resistance to corrosion. This product includes a sensor and reservoir to maintain system integrity. Warranty coverage details should be confirmed at the time of purchase, as they may vary by distributor.