What is ABS Braking and How Does it Work?

There’s a lot we take for granted with our cars, including our all-important braking systems. Most of us don’t think twice about our brakes, however, the types of brake system used in our vehicles is a critical aspect of vehicle safety.

If you’ve ever tried to stop a car in a hurry – particularly when the road is slippery – you will have experienced the sudden adrenaline rush and now understand first-hand how challenging and potentially dangerous this scenario could be. However, Anti-lock braking systems (ABS) take much of the challenge and danger out of these tricky braking situations.

With traditional, non-ABS brakes, the task of controlling speed and preventing loss of control is left to the driver. With non-ABS systems, drivers must learn and follow a split-second, specific technique to prevent skidding and maintain maximum tyre grip.

This technique involves learning the correct timing for when to firmly pump and release your brakes in quick succession. Unfortunately, when most people encounter an adrenaline-raising event while driving, they often revert to panicked, automatic reactions.

Having traditional – non-ABS – brakes on a car adds one more thing for the driver to think about. And, if they don’t perform the manual braking technique correctly, there may be devastating consequences.

This is exactly why ABS braking was invented and is now used on all modern cars as a safety feature. Essentially, ABS pumps and releases the vehicle brakes exactly as a driver would, except much faster and with precise timing. A driver using ABS braking only needs to press on the brake pedal and the car takes care of bringing the vehicle safely to a halt.

Here’s a short explanation of the components in an ABS system and how they all work together:

The controller is the ‘brains’ of the braking system; a computer built into the car. It calculates the vehicle’s speed and controls the braking system components according to precisely accurate timing.

The controller works in conjunction with the speed sensors, which identify if and when a wheel is about to lock up and relays this information back to the controller, which then instructs the valves.

The valves, present in each ABS brake line, control the mechanics of the wheel and the pressure on the brakes. Acting on information from the controller, the valve releases pressure on the brakes, acting in tandem with the pump. The valve reduces pressure on the brakes, while the pump adds pressure. Together, they create the rapid brake ‘pump and release’ action that a driver used to have to do manually.

ABS braking is an extremely useful safety feature that continues to save many lives and reduce the risk of harm. It is so valuable that – in New Zealand’s Safer Journeys Plan of 2013-15 – the government included ABS braking as a mandatory safety feature. This means that all new vehicles in New Zealand must have ABS installed, to keep drivers, passengers and pedestrians safe.