Dorman M105118 Brake Master Cylinder

Reliable Brake Master Cylinder for Chevrolet and GMC Vans

The Dorman M105118 brake master cylinder is engineered to restore proper brake hydraulics in Chevrolet and GMC vans, including G10, G20, P20, and P2500 models. Designed with durable cast iron and precise bore diameters, this master cylinder ensures consistent brake fluid pressure for safe stopping performance.

• Compatible with Chevrolet G10, G20, P20, and GMC P2500 models
• Constructed from durable cast iron for long-lasting use
• Includes reservoir for brake fluid storage
• Dual outlet design with rearward outlet size 1/2-20 and secondary outlet thread diameter 9/16-18
• Master cylinder bore diameters of 1.125 and 1.563 inches for accurate hydraulic control

Product Details and Specifications

The Dorman M105118 brake master cylinder features a cast iron body that provides strength and resistance to wear under demanding braking conditions. It includes a reservoir to hold brake fluid, eliminating the need for a separate component. The dual outlet design with two outlets allows for efficient brake fluid distribution, with a rearward outlet size of 1/2-20 and a secondary outlet thread diameter of 9/16-18. The master cylinder bore diameters of 1.125 and 1.563 inches are designed to match the hydraulic requirements of the specified Chevrolet and GMC van models, ensuring proper brake pedal feel and stopping power.

Common Applications and Problem Resolution

• Restores brake fluid pressure in Chevrolet G10, G20, P20, and GMC P2500 vans
• Replaces worn or leaking master cylinders causing brake pedal sinking or sponginess
• Addresses brake fluid reservoir leaks or contamination issues
• Solves inconsistent brake pedal response due to internal cylinder wear
• Improves overall brake system reliability and safety

Installation Notes and Tips

When installing the Dorman M105118 brake master cylinder, ensure the brake fluid reservoir is properly filled and free of contaminants. Bleed the brake system thoroughly to remove air and achieve optimal hydraulic pressure. Note that mounting hardware is not included, so retain original hardware or source compatible fasteners. Verify outlet thread sizes (1/2-20 rearward and 9/16-18 secondary) to ensure proper brake line connections.

Quality Assurance and Warranty

Dorman brake master cylinders are manufactured to meet or exceed OEM specifications, providing reliable performance for Chevrolet and GMC vans. This part is backed by Dorman's quality standards, ensuring durability and consistent operation. Please refer to Dorman's official warranty policy for specific coverage details.