Dorman M390268 Brake Master Cylinder

Reliable Brake Master Cylinder for Ford, Mazda, and Mercury Vehicles

The Dorman M390268 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Ford, Mazda, and Mercury models. Designed with precision, this master cylinder includes a reservoir and sensor to ensure optimal brake system performance.

• Master cylinder bore diameter: 1.063 inches for accurate hydraulic pressure
• Constructed from durable aluminum material for corrosion resistance
• Includes reservoir and sensor for integrated brake fluid management
• Two outlets with rearward outlet size M10 x 1.0 and secondary outlet thread diameter M12 x 1.0
• Compatible with Ford B2300, B3000, B4000, Explorer, Ranger, and Mercury Mountaineer

Product Details and Specifications

This Dorman brake master cylinder (part number M390268) is designed to meet the exacting requirements of brake hydraulics systems in various Ford, Mazda, and Mercury trucks and SUVs. The aluminum construction provides strength and resistance to corrosion, while the 1.063-inch bore diameter ensures consistent hydraulic pressure for reliable braking. The included reservoir and sensor facilitate proper fluid level monitoring and brake system feedback. Featuring two outlets with precise thread sizes (M10 x 1.0 rearward outlet and M12 x 1.0 secondary outlet), this master cylinder integrates seamlessly with the vehicle’s brake lines.

Compatible Vehicles and Applications

This brake master cylinder is compatible with the following makes and models:

• Ford B2300, B3000, B4000 pickups
• Ford Explorer and Ranger SUVs
• Mercury Mountaineer SUV

It is designed specifically for brake hydraulic systems requiring a master cylinder with these specifications, ensuring proper fit and function.

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
• Faulty brake fluid level sensor triggering warning lights
• Brake system failure caused by internal seal deterioration

Installation Notes and Tips

• Ensure brake fluid reservoir is properly filled before installation
• Bleed the brake system thoroughly after replacing the master cylinder to remove air
• Verify thread sizes (M10 x 1.0 and M12 x 1.0) match vehicle brake lines
• Use appropriate tools to avoid damaging aluminum housing or sensor components
• Consult vehicle service manual for torque specifications and mounting procedures

Quality Assurance and Warranty

Dorman manufactures this brake master cylinder to meet or exceed OEM standards for durability and performance. The part number M390268 undergoes rigorous quality control to ensure reliable operation in brake hydraulic systems. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship.