Dorman M390342 Brake Master Cylinder

Reliable Brake Master Cylinder for Nissan Pathfinder and Infiniti QX4

The Dorman M390342 brake master cylinder is engineered to restore proper brake hydraulics in your Nissan Pathfinder or Infiniti QX4. Designed with precision, this aluminum master cylinder includes a reservoir and sensor to ensure consistent brake performance.

Key Features of the Dorman M390342 Brake Master Cylinder

• Master cylinder bore diameter: 1 inch for accurate hydraulic pressure
• Constructed from durable aluminum material for corrosion resistance
• Includes reservoir for fluid storage and sensor for system monitoring
• Two outlets with secondary outlet thread diameter of 10 mm and rearward outlet size M10 x 1.0
• Thread pitch of 1.0 ensures secure fitting
• Package contains the master cylinder only; mounting hardware not included

Detailed Product Description

The Dorman M390342 brake master cylinder is specifically designed for use in Nissan Pathfinder and Infiniti QX4 models, providing a direct replacement for the original component. Its aluminum construction offers durability and resistance to wear, while the included reservoir and sensor support proper brake fluid management and system feedback. The master cylinder features a 1-inch bore diameter, which is critical for maintaining the correct hydraulic pressure needed for effective braking. With two outlets, including a secondary outlet thread diameter of 10 mm and a rearward outlet size of M10 x 1.0, this part ensures compatibility with the brake hydraulic system of the specified vehicles.

Common Applications and Issues Addressed

• Restores brake hydraulic pressure for improved braking response
• Replaces leaking or damaged master cylinders causing brake fluid loss
• Resolves brake pedal sinking or sponginess due to internal seal failure
• Addresses sensor-related brake system warnings or malfunctions
• Corrects issues with brake fluid reservoir leaks or contamination

Installation Notes and Tips

• Ensure brake fluid system is properly bled after installation to remove air
• Verify thread pitch and outlet sizes match vehicle specifications before installation
• Mounting hardware is not included; reuse original hardware or source separately
• Handle the sensor connection carefully to avoid damage during installation
• Consult vehicle service manual for torque specifications and installation procedures

Quality Assurance and Warranty Information

Dorman manufactures the M390342 brake master cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction and integrated sensor contribute to reliable brake system performance. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Refer to Dorman’s official warranty policy for complete terms.