ACDelco 18M932B Brake Master Cylinder Assembly

The ACDelco 18M932B is a professional-grade brake master cylinder assembly built to deliver reliable, consistent braking performance. Constructed using both cast iron and aluminum, this master cylinder is engineered to meet OE standards for fit, form, and function, making it a direct replacement for a wide range of vehicles.

The rubber internal components — including Ethylene Propylene (EPDM) and Styrene Butadiene (SBR) compounds — provide superior resistance to heat, corrosion, and fluid leakage, ensuring long-term durability under demanding braking conditions. The precision piston assembly and return spring work together to help prevent brake drag and premature pad wear.

Key Features:

• Meets SAE J1153 and J1154 brake performance testing requirements
• Pressure tested for safe and confident braking performance
• Cast iron and aluminum construction minimizes stress on the brake booster mounting
• Geometrical tolerances ensure a proper fit between the body and plastic reservoir
• EPDM and SBR rubber components resist heat, corrosion, and leakage
• Piston assembly and return spring help prevent brake drag and premature pad wear
• Ready to bench bleed and install straight out of the box — no assembly required
• Bore Diameter: 1.000 in (25.4 mm)
• Primary Outlet Thread Diameter: 0.5 in (12.7 mm)
• Port Quantity: 1
• Master Cylinder Material: Iron
• Reservoir Included: Yes
• Brake Booster Included: No
• Mounting Bracket Included: No
• Master Cylinder Cap Included: No
• Bleeder Hoses Included: Yes
• OEM / Cross-Reference Part Number: 19175953

The ACDelco 18M932B brake master cylinder is a premium aftermarket replacement engineered for a precise, hassle-free installation that restores full braking confidence.