The brakes and/or calipers on a vehicle refer to a system to slow down a vehicle when needed. In general, this works by increasing the friction between 2 moving parts, where the energy of the movement is transformed into heat. Some vehicles (like electric cars) use secondary systems to either aid in braking, or to use the energy to generate a usable form of energy (like electricity).
Why the use for brakes
When a vehicle is in motion, energy is used to overcome friction in many different areas (the tyres rolling over the road, the air that needs to be pushed aside, friction in bearings etc). When the object is in motion, the energy in contains needs to be transferred into a different form of energy. E=MC2, which loosely means: Energy = Mass x speed(square). A vehicle has a certain mass, and when the speed it moves at increases, the energy the object contains increases as well. When this object needs to be slowed down for whatever reason, this amount of energy needs to go somewhere. The use of friction is a regularly used solution, where the braking systems consists out of 2 objects being pressed against each other. 1 object moves with the vehicle while another object remains stationary. The friction creates heat, which absorbs part of the energy from the moving vehicle. Without brakes, a vehicle has no way to slow down or stop completely. Although extremely common these days, the invention of moving object often begins with getting them into motion, not with stopping that motion.
Different parts in brakes
The brakes in a vehicle can consist out of many different components. Although there is large different between different systems, they often contain a few similar components. These include the brake drum, a type of brake disc, a type of brake shoe and a spring type system to release the brakes.
A few commonly used types of brakes are:
These are often seen on motorcycles and some cars. The disc brake consists out of a rotating disc that is commonly connected to the axle of the moving component and a stationary part that holds the brake shoe and a system that pushes the brake shoe against the brake disc. The component that pushes the brake shoe against the braking disc is usually a cylinder called the “caliper”. Many cars have disc brakes on the front wheels, whereas the rear wheels can be drum brakes. These are recognized by the clearly visible round brake disc.
Drum brakes consist out of a drum that covers over the braking system. The brake shoes are inside the drum and are pushed outwards when braking, pressing against the inside of the drum. The drum operates in a similar way to the brake disc. The brake shoes are on the inside and have a noticeably different shape to the brake shoes on disc brakes. Some vehicles have special brake discs that also have a drum type inside. This allows the brake disc to be used as a brake disc when braking normally, and to be used as a drum brake for the handbrake (or parking brake). With many vehicles, the drum brakes or on the rear wheels of the vehicle.
Electric vehicles can have a secondary braking systems, that functions are a type of dynamo, the dynamo creates enough friction to 1. slow down the vehicle substantially and 2. generate electricity to charge up the batteries. Some cars, like the Tesla Model S, can generate enough energy from braking to compensate for the energy used to accelerate again. Some older type of cars use an energy-converter as a braking system that can function in a similar way by using the braking force to spin up a component which rotational energy can later be used to accelerate again.
In some rare cases, the term “electric brake” refers to brakes that are not powered by hydraulics, but are activated by an electric signal.
Cleaning brakes and calipers
Brakes are known to be a common cause of fallout, which is a form of metal dust that creates a dull, grey film on wheels. This brake dust originates from the 2 metal parts (brake disc and brake shoe) rubbing against each other. Just like the sawdust you can get when sanding wood, the brake parts create metal “sawdust”. Although the term “Fallout” is a bit incorrect, the term brake dust is also used. The product used to dissolve these particles, and make it easier to remove them, is called a “fallout remover”.
Other dirt than can accumulate in/on the braking system comes from dirt and dust thrown up from the road surface. This can be sooth, tar, mud, sand, organic material and rubber particles. Because the heat generate when braking, the braking system can become very hot, baking in the contamination. Neglected braking systems can be very difficult to clean completely without strong chemicals or techniques. When cleaning brakes, it should be noted that the braking systems uses grease to keep the components moving smoothly, when cleaning is done with strong chemicals, this grease can also be removed. It is recommend to either take caution while cleaning, or to replace the grease after cleaning to avoid the systems seizing up.