Nowadays, with automakers more concerned with the number of accidents, they have made their brake system into two circuits. This allows one pair to continue working in such case that there is a fluid leak. The brake master cylinder is responsible for supplying the pressure to the two circuits. And a combination valve warns the driver in case a problem occurs in the brake system. The brake master cylinder is a part of the brake system of your Mazda. It is attached to the brake booster. And using two pistons in the same cylinder it allows the driver to put pressure to the braking hydraulic system. When the driver steps on the brake pedal, it pushes the primary piston through a linkage. Pressure builds in the cylinder and lines as more pressure is applied on the brake pedal. The pressure between the primary piston and the secondary piston forces the second piston to compress the fluid in its circuit and thus putting the fluid for the caliper. And this is the fluid necessary to move the pistons that pushes the brake pads against the rotor that put a stop to the wheels. Each part is doing its function as one whole system. Atop the brake master cylinder is a plastic brake fluid reservoir where the brake fluid is housed and needs to be flushed yearly to ensure that your Mazda brake master cylinder last for years. In case of leak, the pressure between the primary and secondary cylinders is lost thus the braking power will be affected. It is best that you maintain regular check-up of a qualified mechanic on your brake system. Major accidents can happen if one of these main components fails. Order your Mazda brake master cylinder from our store, where you are assured of getting premium quality auto part.