Master Cylinder

Category: automotive

The component that converts the force of your foot on the brake pedal into hydraulic pressure.

The master cylinder is the "heart" of the brakes. If it starts leaking internally, the pedal will sink to the floor (spongy pedal). It sends the fluid down the lines to all four wheels.

Common Examples

• The spongy brake pedal was a clear symptom of a failing master cylinder that could no longer hold hydraulic pressure.
• Replacing the master cylinder is a critical braking repair that must be followed by a thorough system "bleed" to remove all air bubbles.