Dorman M390140 Brake Master Cylinder

Reliable Brake Master Cylinder for Nissan Altima

The Dorman M390140 brake master cylinder is engineered to restore proper brake hydraulics in your Nissan Altima. Designed with precision, this aluminum master cylinder includes a reservoir and features a 0.938-inch bore diameter to ensure consistent brake fluid pressure.

• Compatible with Nissan Altima models requiring a 0.938-inch bore diameter master cylinder
• Constructed from durable aluminum for corrosion resistance and longevity
• Includes an integrated reservoir for brake fluid
• Equipped with four outlets for efficient brake fluid distribution
• Rearward outlet sizes: M10 x 1.0 and M18 x 1.0 thread diameters
• Secondary outlet thread diameter matches rearward outlets for compatibility

Product Details and Specifications

The Dorman M390140 brake master cylinder is designed specifically for Nissan Altima vehicles, providing a direct replacement for the original part. Its aluminum construction offers a balance of strength and lightweight performance, reducing the risk of corrosion over time. The master cylinder bore diameter of 0.938 inches is critical for maintaining proper hydraulic pressure within the brake system. This unit includes a reservoir to hold brake fluid, ensuring consistent fluid supply during braking. With four outlets, it supports multiple brake lines, and the rearward outlet sizes of M10 x 1.0 and M18 x 1.0 thread diameters allow for secure connections to the brake hydraulics system.

Common Applications and Problem Resolution

• Restores brake pressure in Nissan Altima brake systems with failing master cylinders
• Addresses brake fluid leaks caused by worn or damaged master cylinders
• Eliminates spongy or unresponsive brake pedal feel due to internal cylinder wear
• Replaces master cylinders with corroded or damaged aluminum bodies
• Ensures proper brake fluid distribution through multiple outlets for balanced braking

Installation Notes and Tips

Installation of the Dorman M390140 brake master cylinder requires careful attention to brake fluid handling and bleeding procedures. Since mounting hardware is not included, retain original mounting components or source compatible hardware separately. Ensure all brake lines are properly connected to the correct outlet threads (M10 x 1.0 and M18 x 1.0) to prevent leaks. After installation, thoroughly bleed the brake system to remove air and verify proper brake pedal feel before driving.

Quality Assurance and Warranty

Dorman manufactures the M390140 brake master cylinder to meet or exceed OEM specifications for Nissan Altima vehicles. The aluminum construction and precise bore diameter contribute to reliable brake system performance. While specific warranty details are not provided, Dorman products typically come with a limited warranty covering defects in materials and workmanship. Consult product documentation or the manufacturer for exact warranty terms.