Brakes are an essential component for the proper operation of a vehicle and the safety of the occupants and others on the road. However, outside of automobile enthusiasts and mechanics, many individuals do not understand how the braking system functions. Many people might not think braking on a car is a very complicated process because it seems fairly simple, however, this is not the case. The entire brake system, technology and its evolution is fairly complex.
Since the 1970's, automotive braking systems have undergone several innovations to improve a car’s stopping capabilities. While still maintaining the primary function of slowing and stopping forward motions, modern braking systems assist drivers in many more ways than just stopping the vehicle. Without the developed braking systems that have been implemented and mandated through the years, cars and roads wouldn’t be as safe as they are today.
There are several parts that make up a car’s braking system. Today the most popular and fairly standard brakes are disc brakes and they are typically used on all four wheels. There are also drum brakes, but those are typical on older cars or found only on the car’s rear wheels. In addition to discs or drums, the braking system also consists of brake calipers, friction/brake pads, hydraulic lines, brake fluid and a master cylinder and each of those parts work together to make a car stop.
When the driver has a need for braking, the driver presses the brake pedal. Depending on a car’s braking system, pressing the brake pedal activates the master cylinder (either electronically or by linkage) and increases pressure in the hydraulic system which forces fluid through the brake line into the caliper system. Once the fluid reaches the brake calipers, the fluid causes the brake calipers to press against a piston which squeezes brake pads against the disc rotor (attached to the wheel) and that creates enough friction to slow down the wheels.
Some vehicles are equipped with "drum" systems where the principle is the same but the pressure is applied by the friction pads applying pressure to the inside walls of the drum, and thus slowing the motion of the wheel. These types of systems are being slowly phased out and are typically found on light trucks or larger cargo style vans.
In addition to a car’s braking system, there are also other types of systems in place to help make braking safer. Anti-lock brakes are one of those additional systems that are very beneficial.
Anti-lock systems function in a similar fashion with the added component of a sensor system that detects the tractive effort or speed on an individual wheel. During braking, if the system detects an abnormal wheel speed in comparison to the other wheels, the system will then adjust the pressure to maintain proper friction but will not allow the wheel to cease motion or "lock up" until parity is restored. ABS systems can under some situations adjust the braking pressure up to 15 times a second to allow for proper vehicle control. While ABS system also prevents wheel locking under brake pressure, under usual circumstances ABS systems also reduce the braking distance required to be the vehicle to the full stop. However, some surfaces such as loose gravel or snow can actually increase braking distances, regardless of ABS.
The evolution of brakes hasn’t stopped since the first cars were created in the early 19th century and this is still true today. In March, the NHTSA and a group of auto manufacturers made a deal to make auto-braking a standard feature on new light-duty vehicles by 2022. (https://www.nowcar.com/blog/archive/auto-braking-standard-on-new-cars-by-2022/).
In fact, within the last few years, brakes have even become a factor in helping improve the energy efficiency of cars by way of regenerative braking. Used in hybrid and electric vehicles, regenerative braking is a method of braking in which energy is extracted from the parts braked, to be stored and reused.
Brakes are vital to the safe operation of a motor vehicle and almost every vehicle that engages in forward motion, large or small, it equipped with some form of a braking system. Understanding the basic operation and components in a braking system can help anyone understand more about their individual vehicle or automobile. As a driver, understanding the basics of brakes can help one be a better-prepared driver for the challenges faced on the modern road. As a car owner, learning about brakes can help you understand the parts and systems that require regular maintenance.