Turn pedal effort into the hydraulic pressure your brakes rely on with the Dorman First Stop Brake Master Cylinder, part number M101266. It is a direct-fit replacement for many Chevrolet and GMC trucks and vans, including the 1975-1981 Chevrolet P30, the 1975-1983 Chevrolet G30 and the 1979-1984 GMC P2500. See the Buyer's Guide tab for the full list of applications.
Dorman engineered this master cylinder to replicate the design, function and performance of the original unit on the listed vehicles. It is built from new, high-quality materials for a safe and durable replacement.
- Cast iron housing: the cylinder housing is made to match the original part's casting material for similar performance.
- EPDM rubber components: every rubber component uses a high-quality EPDM compound that resists glycol-based brake fluid.
- 100% new: made entirely from new materials for quality and safety.
- SAE standards: made to meet rigorous SAE International standards.
Specifications: 1.25 in bore diameter, two outlets and a 1/2-20 rearward outlet size. A reservoir is included; mounting hardware and a sensor are not. Country of origin: China.
Signs a master cylinder may need replacing include a brake pedal that feels soft or slowly sinks, or brake fluid leaking from the unit. Diagnose the cause before replacing; if the master cylinder is at fault, this unit is designed to replace it. The package contains one master cylinder, and the listed applications use one.
