Dorman - First Stop Brake Master Cylinder P/N:M39578

Convert brake-pedal force into the hydraulic pressure your brakes need with the Dorman First Stop Brake Master Cylinder M39578. It drops in as a direct-fit replacement for the 1978 and 1985-1995 Chevrolet G20, the 1985-1993 Chevrolet Astro, 1985-1995 Chevrolet G10, 1985-1989 Chevrolet P20, 1985-1995 GMC G1500, 1985-1995 GMC G2500, 1985-1989 GMC P2500, and 1985-1993 GMC Safari (all engines) — engineered to match the design, function, and performance of the original unit on these applications.

• 100% new: built entirely from new materials, not remanufactured.
• Aluminum housing: constructed to match the casting material of the original part for similar performance.
• EPDM rubber components: resist glycol-based brake fluid for a durable seal.
• SAE-standard build: made to meet rigorous SAE International standards.

The cylinder ships with the fluid reservoir included and has two outlets, including a 1/2-20 rearward outlet. Mounting hardware is not included, and no sensor is supplied — consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: China. If a worn or leaking master cylinder is the cause of a sinking or spongy brake pedal, this unit replaces it; diagnose the cause before replacing. Manufacturer part number M39578.