General description of the braking system (Mondeo 2)

A dual-circuit hydraulic brake system is a system with a diagonally divided hydraulic drive. Accordingly, a separate brake circuit is installed for the front wheel and the diagonally opposite rear wheel.

The master brake cylinder converts the mechanical force of pressing the brake pedal into hydraulic force. It is responsible for quickly reducing the pressure in the system after releasing the pedal.

The brake booster is located on the left in the engine compartment behind the main brake cylinder, connected to the exhaust manifold by a pipeline. When braking, the elastic membrane reacts to the difference in pressure values between the outside air and in the exhaust manifold. As a result, the membrane additionally presses on the piston of the main brake cylinder.

Brake fluid in brake lines and cylinders is a mixture of glycol, polyglycol ether and a couple of other components. It is most often yellowish or colorless, usually poisonous and aggressive towards paintwork, but does not corrode metal and rubber parts of the brake system, even at a temperature of -40°C it remains liquid and, despite its fluidity, has a very high boiling point - about +290°C.

Brake fluid is very hygroscopic. If the proportion of water in it is 2.5%, then the boiling point decreases to +150°C. Under heavy loads on the brakes, this is very dangerous. Near heated brakes, steam bubbles can form in the hydraulic fluid, which are compressed, and as a result, the brake pedal can fall through (in this situation, a quick bleed of the hydraulic drive sometimes helps).