Dorman - First Stop Brake Master Cylinder P/N:M630377

Turn brake-pedal pressure into the hydraulic force that operates your brakes with the Dorman - First Stop Brake Master Cylinder M630377. It drops in as a direct-fit replacement for the 2003-2005 Chevrolet Astro [All] and 2003-2005 GMC Safari [All], where it houses the pistons that pressurize brake fluid and send it through two outlets to the brake system.

• 100% new: made entirely of new materials, not remanufactured.
• Aluminum housing: constructed to match the casting material of the original part for similar performance.
• Durable EPDM seals: all rubber components use a high-quality EPDM compound for resistance to glycol-based brake fluid.
• Built to spec: engineered to match the original's design, function, and performance on the listed applications, and made to meet rigorous SAE International standards.

Specs: 1.25 in bore diameter, 2 outlets, and a 1/2-20 secondary outlet thread. The reservoir is included; a sensor and mounting hardware are not included — consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: China. If a failing master cylinder is the cause, signs may include a sinking or spongy brake pedal or fluid leaks; diagnose the cause before replacing.

Interchange: 174-1006 · 1741006 · 100-2978 · 1002978 · 13-3101 · 133101 · 10-3101 · 103101 · 130.66050 · 131.66050 · 355-47177 · 35547177 · 18048897 · M4082 · NM4082 · MC390830 · F142298 · MC142298 · Manufacturer part number M630377