Master Cylinder

Browse New OEM brake master cylinders for GM vehicles. Our factory-original master cylinders are sourced from GM surplus — the correct bore diameter, reservoir capacity, and outlet port configuration for your vehicle's hydraulic brake system.

The master cylinder generates the hydraulic pressure that operates all four wheel brakes. Master cylinder bore diameter is precisely matched to your vehicle's brake caliper piston area and brake pedal ratio — ensuring the correct pedal effort and travel for full brake system pressure. An incorrect bore diameter changes brake feel and pedal stroke.

Master cylinder replacement requires brake system bleeding and pedal adjustment. Verify part numbers against your vehicle's brake system configuration before ordering.