The brake master cylinder is an assembly that transfers the level of pressure the driver applies to the brake pedal to the calipers and drums. Pressing the brake pedal actuates a piston inside the master cylinder, forcing brake fluid or hydraulic fluid out of a reservoir through the brake lines and into the slave cylinders. The pressure causes pistons to press out of the slave cylinders, compressing the brake pads against the rotors or shoes, thus slowing the wheels’ rotations. There are two chambers inside the master cylinder to allow for braking front and rear at the same time, allowing the system to work simultaneously.
If your vehicle begins leaking brake fluid or the brake pedal gets soft, your master cylinder could be failing. If the brakes are not as responsive, you hear a grinding noise, or there’s a reduction in braking power, the cylinder could be defective.
Replacing the master cylinder can start around $200 to $300 for the part, plus labor.
See also: What Are New Brakes? What Are Brake Rotors? What Is a Brake Slave Cylinder?
