Dorman M39640 Brake Master Cylinder

Reliable Brake Master Cylinder for Dodge and Mitsubishi Vehicles

The Dorman M39640 brake master cylinder is engineered to restore proper brake hydraulics in select Dodge and Mitsubishi models. Designed with a cast iron body and integrated reservoir, this master cylinder ensures consistent brake fluid pressure for safe stopping performance.

• Master cylinder bore diameter: 0.938 inches for precise hydraulic control
• Durable cast iron construction for long-lasting service
• Includes reservoir and sensor for complete brake system integration
• Two outlets with rearward outlet size M10 x 1.0 and thread pitch 1.0
• Compatible with Dodge Ram 50, Dodge Mighty Max, Mitsubishi Montero, and Mitsubishi Raider

Product Details and Specifications

The Dorman M39640 brake master cylinder features a cast iron material that provides strength and resistance to wear under demanding braking conditions. Its 0.938-inch bore diameter is designed to deliver consistent hydraulic pressure, essential for effective brake operation. This unit includes a reservoir and sensor, allowing for seamless integration with the vehicle’s brake fluid monitoring system. The master cylinder has two outlets, with a secondary outlet thread diameter of 10 mm and a rearward outlet size of M10 x 1.0, ensuring compatibility with the brake lines on the specified Dodge and Mitsubishi models.

Compatible Vehicles and Applications

This brake master cylinder is compatible with the following vehicles:

• Dodge Ram 50
• Dodge Mighty Max
• Mitsubishi Montero
• Mitsubishi Raider

It is designed to replace the original master cylinder in these models, restoring proper brake hydraulics and improving overall braking performance.

Common Issues Addressed by This Master Cylinder

• Spongy or unresponsive brake pedal
• Brake fluid leaks from the master cylinder or reservoir
• Brake warning light activation due to sensor failure
• Reduced braking efficiency or uneven brake pressure
• Contaminated or deteriorated brake fluid reservoir

Installation Notes and Tips

• Ensure the brake system is properly bled after installation to remove air pockets
• Verify thread pitch and outlet sizes match vehicle brake lines before installation
• Use appropriate brake fluid as specified by the vehicle manufacturer
• Check sensor connections for proper operation after installation
• Mounting hardware is not included; reuse existing hardware or source separately

Quality Assurance and Warranty

Dorman manufactures this brake master cylinder to meet or exceed OEM specifications, using cast iron for durability and reliability. The included sensor and reservoir are designed for seamless integration with the vehicle’s brake system. While mounting hardware is not included, the product undergoes quality checks to ensure fit and function. Warranty coverage details should be confirmed with the point of purchase or manufacturer documentation.