Do you know why the brake pedal becomes very hard when you turn off the car engine? It is one of the first surprises that leave you dumbfounded when you are towing the car, but also the advantage that still pushes the Manufacturers to install the hydraulic braking system tested for years. Driving the car it is normal to take the mechanisms behind each system for granted, but it is equally important to know how to distinguish a failure from the normal operation of pads, disks and drums . Check out the video below with Konstantin Vikulov , Head of Quality Brake Pads at TRW how the brakes work .
BRAKES AND HEAT, ENEMY OF OLD DATE – The invention of disc brakes dates back to the early 1900s by Frederick William Lanchester, although the system has undergone many application developments over the years to boast multiple authorship. As Konstantin Vikulov of TRW also explains in the video above, the drum brakes were heavy, they dispersed the heat badly and they suffered terribly from the fading (decrease of braking force due to overheating, see here what happens to the economic brakes that get too hot) . And so the need to find a more reliable and safe system in the prolonged use of brakes: the disks . Today, as then, the brakes exploit the strong frictionwhich is created between discs and pads (here you can see how the brake pads are produced) to transform the kinetic energy into heat, the Achilles heel of the brakes; finding, however, a stable position in the circles, it has been possible to better facilitate its cooling. But how much force is needed on the pedal to brake a car traveling at 100 km / h? Not much thanks to the engine.
THE ENGINE REDUCES THE EFFORT – The pads slow down the disc, and therefore the car, because the pump operated with the brake pedal activates the caliper pistons; nothing simpler. But why is brake fluid so important? By the Pascal principle, the force applied to the brake pedal is transferred to the liquid contained in the circuit, pushing it until the caliper pistons are activated. Since liquids are generally incompressible, the brake booster has been added to the brake pump.