Dorman - First Stop Brake Master Cylinder P/N:M40000

Turn brake-pedal effort into the hydraulic pressure that operates the whole brake system with the Dorman First Stop Brake Master Cylinder, part number M40000. It drops in as a direct-fit replacement across a broad list of 1960s applications — including the 1962-1966 Chevrolet Impala, Bel Air, Biscayne and Corvair, the 1964-1966 Chevrolet Chevelle, the 1965-1966 Buick Skylark, the 1964-1966 Oldsmobile Cutlass, the 1962-1966 Pontiac Bonneville and Catalina, and the 1964-1966 Jeep Wagoneer; see the Buyer's Guide tab for the full list.

• Cast iron housing: the cylinder body is cast iron, built to perform like the original casting.
• Bore and outlet: 1 in bore with a single outlet sized 7/16-24.
• EPDM rubber components: the rubber parts use a high-quality EPDM compound for resistance to glycol-based brake fluid.
• 100% new: made entirely of new materials — not remanufactured — and produced to meet SAE International standards.

The master cylinder converts the force at the pedal into hydraulic pressure that pushes fluid to the wheel circuits. Signs the original may need replacing include a sinking or spongy pedal or fluid seepage at the cylinder; diagnose the cause before ordering. A reservoir is included; a sensor and mounting hardware are not — consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: Taiwan. Manufacturer part number M40000.