Dorman M390121 Brake Master Cylinder

Overview of Dorman Brake Master Cylinder for Nissan Maxima

The Dorman M390121 brake master cylinder is designed specifically for Nissan Maxima models, providing reliable brake hydraulics performance. This aluminum master cylinder includes a reservoir and sensor, engineered to meet the precise specifications required for optimal braking function.

• Compatible with Nissan Maxima vehicles
• Master cylinder bore diameter of 0.938 inches
• Constructed from durable aluminum material
• Includes reservoir and sensor for integrated brake system monitoring
• Four outlet ports with rearward outlet size M10 x 1.0 and thread pitch 1.0
• Secondary outlet thread diameter of 10 mm
• Mounting hardware not included

Detailed Product Features and Specifications

The Dorman M390121 brake master cylinder features a 0.938-inch bore diameter, ensuring precise hydraulic pressure control for the Nissan Maxima brake system. Its aluminum construction offers corrosion resistance and long-term durability under demanding conditions. The included reservoir allows for proper brake fluid storage, while the integrated sensor supports brake system diagnostics and safety monitoring. This master cylinder has four outlets, including a rearward outlet sized M10 x 1.0 with a 1.0 thread pitch, and a secondary outlet thread diameter of 10 mm, facilitating proper brake line connections. Note that mounting hardware is not included with this part.

Common Applications and Problem Resolution

This brake master cylinder is used to replace worn or damaged units in Nissan Maxima brake hydraulic systems. It addresses several issues, including:

• Brake pedal sinking or sponginess due to internal leaks
• Brake fluid leaks from a failing master cylinder reservoir or seals
• Inconsistent brake pressure affecting stopping performance
• Faulty brake fluid level sensor triggering warning lights
• Corrosion or wear compromising hydraulic integrity

Installation Notes and Tips

When installing the Dorman M390121 brake master cylinder on a Nissan Maxima, ensure the brake system is properly bled to remove air and maintain hydraulic pressure. Verify compatibility with your vehicle’s model year and brake line fittings, especially the M10 x 1.0 rearward outlet thread size. Since mounting hardware is not included, retain or source appropriate fasteners for secure installation. Handle the aluminum component carefully to avoid damage during installation.

Quality Assurance and Warranty Information

Dorman manufactures this brake master cylinder to meet or exceed OEM specifications for Nissan Maxima brake hydraulics. The part undergoes quality control testing to ensure reliable performance and durability. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Consult product documentation or the supplier for exact warranty terms.