ACDelco 18M198B Professional Brake Master Cylinder Assembly

The ACDelco 18M198B Professional Brake Master Cylinder is a premium aftermarket replacement brake master cylinder engineered to deliver reliable, consistent hydraulic braking performance. Designed to meet expectations for fit, form, and function, this master cylinder is a dependable solution for restoring proper braking system operation.

Key Features:

• Aluminum and iron castings provide a high-quality, durable construction suitable for the demands of daily driving
• Ethylene Propylene (EPDM) and Styrene Butadiene (SBR) rubber internal components offer superior resistance to heat, corrosion, and fluid leakage
• Ready to bench bleed and install straight out of the box — no additional assembly required
• Manufactured to meet or exceed OEM specifications for precise fit and consistent braking performance
• Part of ACDelco's Professional line of aftermarket brake components, backed by GM engineering standards

The ACDelco 18M198B brake master cylinder is the central hydraulic component of your vehicle's braking system, converting pedal force into hydraulic pressure to actuate the wheel brakes. Replacing a worn or leaking master cylinder restores proper pedal feel and ensures confident, safe stopping power.