Dorman M390378 Brake Master Cylinder

Reliable Brake Master Cylinder for Dodge Dakota and Jeep Wrangler

The Dorman M390378 Brake Master Cylinder is engineered to restore proper brake hydraulics for Dodge Dakota and Jeep Wrangler models. Designed with durable aluminum construction and a built-in reservoir, this master cylinder ensures consistent brake fluid delivery and reliable stopping power.

Key Features of the Dorman M390378 Brake Master Cylinder

• Master cylinder bore diameter: 1 inch for precise hydraulic pressure
• Constructed from aluminum for corrosion resistance and durability
• Includes an integrated reservoir for brake fluid storage
• Equipped with two outlets to support dual-circuit brake systems
• Rearward outlet size: M10 x 1.0 thread for secure fitting
• Secondary outlet thread diameter: M12 x 1.0 with 1.0 thread pitch
• Package contains the master cylinder only; mounting hardware not included

Detailed Product Description

The Dorman M390378 Brake Master Cylinder is specifically designed for use in Dodge Dakota and Jeep Wrangler vehicles, providing a direct replacement for the original equipment part. Its aluminum body offers enhanced resistance to corrosion and wear, extending the service life of the brake system. The 1-inch bore diameter ensures proper hydraulic pressure is maintained, while the included reservoir allows for efficient brake fluid management. With two outlets featuring precise thread sizes (M10 x 1.0 rearward and M12 x 1.0 secondary), this master cylinder supports dual-circuit brake systems commonly found in these vehicles.

Common Applications and Issues Addressed

• Restores brake fluid pressure in Dodge Dakota and Jeep Wrangler brake systems
• Replaces leaking or damaged master cylinders causing brake fluid loss
• Eliminates spongy or unresponsive brake pedal feel
• Resolves brake system failure due to worn internal seals or corrosion
• Supports safe and consistent braking performance under normal driving conditions

Installation Notes and Tips

• Ensure brake fluid reservoir is properly filled before installation
• Bleed the brake system thoroughly after installation to remove air
• Verify thread sizes (M10 x 1.0 and M12 x 1.0) match vehicle brake lines
• Mounting hardware is not included; reuse existing hardware or source separately
• Consult vehicle service manual for torque specifications and installation procedures

Quality Assurance and Warranty Information

Dorman manufactures the M390378 Brake Master Cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction and precise machining ensure long-term reliability in brake hydraulics. While mounting hardware is not included, the part is backed by Dorman's quality control processes. Please refer to Dorman's official warranty policy for coverage details.