Brake types, how they work, and the differences between ICE, hybrid and electric cars
The brake system slows down and stops the car by converting kinetic energy into heat — and in hybrids and EVs, partly recovering it back into the battery. Discs or drums create friction under pressure from the pads, hydraulics transmit pedal force to all wheels at once, and electronic systems like ABS keep the wheels from locking up and losing control. The design and load on these parts differ by vehicle type — heavy electric cars brake quite differently from lighter ICE cars.
From a simple drum to regenerative braking
A caliper presses pads against a spinning disc from both sides, creating friction. Delivers stable, strong braking even when hot, which is why it's used on the front axle of nearly every car and the rear axle of most modern ones.
Components
Shoes press outward against the inside of a spinning drum. Simpler and cheaper than a disc, better sealed against dirt, but cools worse — used on the rear axle of budget cars and as the parking brake mechanism.
Components
Holds the car in place mechanically, independent of the hydraulic system. Increasingly replaced in modern cars by an electric actuator built directly into the rear caliper.
Components
The electric motor switches into generator mode and slows the wheels, returning part of the kinetic energy to the traction battery. Works alongside the mechanical brakes, reducing their wear and extending range.
Components
The principle is similar, but load distribution and wear differ significantly
All kinetic energy during braking turns into heat at the discs and pads. It's the only way to slow down, so discs, calipers and pads are built for constant heavy use and need regular replacement as they wear.
The electric motor handles part of the braking through regeneration, especially at low and medium speed, while the mechanical brakes step in for hard or sudden pedal pressure. A control unit blends the two smoothly, invisibly to the driver.
Regeneration is used most of the time — up to fully one-pedal driving — so the mechanical brakes wear far more slowly. But because of the battery's weight, discs and calipers are made larger to guarantee strong emergency braking, and the rare use of the mechanical brakes means discs need more frequent checks for corrosion.
The core elements shared by most brake systems
Click a node to see its description in the cards below
Spins with the wheel and creates friction when the pads clamp onto it, dissipating kinetic energy as heat.
The caliper presses the pads against the disc from both sides under brake fluid pressure, generating braking force.
Converts pedal pressure into brake fluid pressure, which is sent to all wheels at once.
Rapidly releases and restores brake pressure dozens of times a second, keeping the wheels from locking up and losing control during hard braking.
Carry brake fluid pressure from the master cylinder to each wheel through a sealed hydraulic circuit.
Uses engine vacuum (or an electric pump in hybrids and EVs) to amplify pedal pressure, reducing the effort the driver needs to apply.