ACDelco 18M1261B Professional Brake Master Cylinder Assembly

The ACDelco 18M1261B is a Professional-grade brake master cylinder assembly engineered as a direct-fit replacement for OEM hydraulic braking systems. Constructed using both cast iron and aluminum, this master cylinder delivers the structural integrity needed to handle the demands of daily driving without placing excess stress on brake booster mounting hardware.

Key Features:

• Meets brake performance requirements of SAE J1153 and J1154 testing standards for reliable, quality braking
• Pressure tested prior to shipping to ensure safe and confident braking performance
• Cast iron and aluminum construction minimizes stress on brake booster mounting
• Precision geometric tolerances ensure proper fitment between the cylinder body and plastic fluid reservoir
• Internal piston assembly and return spring design helps prevent brake drag, reducing premature pad and rotor wear
• EPDM (Ethylene Propylene) and SBR (Styrene Butadiene) rubber seals provide superior resistance to heat, corrosion, and fluid leakage
• Includes bleeder hoses, reservoir, and master cylinder cap — ready to bench bleed and install straight out of the box
• Backed by ACDelco's 12-month / unlimited-mile warranty

The ACDelco 18M1261B is manufactured to meet OEM fit, form, and function standards, making it a trusted choice for professional technicians and DIY mechanics seeking a quality brake master cylinder replacement.