Dorman M39961 Brake Master Cylinder

Overview of the Dorman Brake Master Cylinder M39961

The Dorman Brake Master Cylinder M39961 is designed specifically for Chevrolet Astro and GMC Safari models. This brake hydraulics component ensures reliable brake fluid pressure for safe and consistent braking performance.

• Master cylinder bore diameter: 1.25 inches
• Constructed from durable aluminum material
• Includes reservoir for brake fluid
• Two outlet ports for brake line connections
• Rearward outlet size: 1/2-20 thread
• Secondary outlet thread diameter: 9/16-18
• Mounting hardware not included

Detailed Product Description

The Dorman M39961 brake master cylinder is engineered with a 1.25-inch bore diameter to provide precise hydraulic pressure control for the braking system. Made from aluminum, this master cylinder offers corrosion resistance and long-lasting durability. It comes with an integrated reservoir to hold brake fluid, eliminating the need for a separate component. The unit features two outlets, including a rearward outlet with a 1/2-20 thread size and a secondary outlet with a 9/16-18 thread diameter, allowing for proper brake line connections. This part is compatible with Chevrolet Astro and GMC Safari vehicles, ensuring a direct fit and proper function.

Common Applications and Issues Addressed

• Restores proper brake fluid pressure in Chevrolet Astro and GMC Safari models
• Replaces worn or leaking master cylinders causing brake pedal sponginess
• Solves brake fluid leaks from damaged or corroded master cylinders
• Addresses inconsistent braking performance due to internal seal failure
• Improves brake system reliability after component wear

Installation Notes and Tips

• Ensure brake system is properly bled after installation to remove air
• Verify thread sizes (1/2-20 rearward outlet and 9/16-18 secondary outlet) match brake lines
• Use appropriate brake fluid as specified by vehicle manufacturer
• Mounting hardware is not included; reuse existing hardware or source separately
• Inspect brake lines and fittings for wear or damage during installation

Quality Assurance and Warranty

Dorman manufactures the M39961 brake master cylinder to meet or exceed OEM specifications for Chevrolet Astro and GMC Safari vehicles. The aluminum construction provides corrosion resistance and durability under normal operating conditions. While mounting hardware is not included, the product undergoes quality checks to ensure proper fit and function. Warranty coverage details should be confirmed with the point of purchase or manufacturer.