ACDelco 18M249 Professional Brake Master Cylinder Assembly

The ACDelco 18M249 Professional Brake Master Cylinder Assembly is a premium replacement brake master cylinder engineered to restore safe, reliable stopping power. Constructed using both aluminum and iron castings, this unit is built to deliver OE-level fit, form, and function for a wide range of vehicles.

Key Features:

• Dual-material construction — aluminum and iron castings for strength and durability
• EPDM and SBR rubber seals — Ethylene Propylene (EPDM) and Styrene Butadiene (SBR) components provide superior resistance to heat, corrosion, and leakage
• 1.5-inch bore diameter — iron master cylinder body designed for proper hydraulic pressure output
• Reservoir included — complete assembly with cap, no additional purchases needed
• Bleeder hoses included — ready for bench bleeding straight out of the box
• 2-port, 2-mounting-hole design — matches OE configuration for a straightforward installation
• SAE J1153 and J1154 compliant — meets brake performance testing requirements for reliability and safety
• Pressure tested — factory verified to ensure safe and confident braking performance
• No assembly required — bench bleed and install right out of the box

Backed by ACDelco's 24-Month/Unlimited Mile Warranty, the 18M249 is a trusted choice for restoring your vehicle's hydraulic brake system with confidence.