Anti-lock braking systems – how ABS works and how to know if yours needs service.
At Milito’s Auto Repair, we receive inquiries on a daily basis. People reach out for a variety of things such as service requests, general questions, and the like. We pride ourselves on being readily available to provide answers for anything that our valued customers want to know about.
Recently, an email came through our website’s contact form with a pretty straightforward service request. Raul’s ABS dashboard light was on in his Toyota Highlander, and he was in need of service. After he described the issue with this SUV, the message closed with, “How does ABS work, anyway?”
First, we’d like to thank Raul for reaching out with a question we hear often. Let’s take a closer look at how ABS works and what it’s designed to do.
History of ABS
Anti-Lock Braking Systems – more commonly known as ABS – was originally invented in 1929 as an anti-skid mechanism for aircraft. The braking systems, which became mandatory in the US and EU in 2013, first appeared as features of Ford and Chrysler vehicles in the 1970s. Today, ABS braking systems are standard equipment on nearly every modern vehicle produced.
Anti-Locking Brake Systems
The primary function of ABS is right there in the name. ABS systems are designed to prevent the brakes from locking up during heavy braking. Contrary to popular belief, anti-lock braking systems aren’t actually designed to help cars stop sooner. While they do generally improve stopping distance, the primary purpose is to prevent the wheels from locking in place under heavy braking, working to prevent skids and help the driver maintain control.
In many ways, the concept of anti-lock braking is essentially the same idea as manually pumping your brakes on a slick surface. A wheel locked in place has less traction and is more likely to slide, where a “pumped” brake will slow the wheel (and the vehicle) while still allowing tread, steering, and acceleration to work as well.
ABS System Basics
For the ABS system to work, the vehicle needs to know when to engage the ABS. Speed sensors located on each wheel (or in some vehicles, the differential) deliver information to the system, controlling valves that regulate the pressure applied to the brakes. How your ABS system works depends on the make, model, and year of your vehicle, but these valves generally allow for a few important things.
In one position, pressure flows freely from the master cylinder, and the pressure you apply to the pedal is applied to your brakes. In another, the valves regulate this pressure, preventing a harder press of the pedal from increasing pressure on the brake. The valves are also capable of releasing some of the pressure from the brake, with pumps to reapply pressure as needed.
With a fully functioning anti-lock braking system, your brakes “pump” automatically. That means that, whether you’re in an emergency stop or slowing down in slippery conditions, pumping your brakes can increase stopping distance. As your ABS engages, let the system do the work!
Anti-lock braking systems are an important safety measure, and making sure the ABS system in your vehicle is in working order could make the difference between an abrupt stop and a costly fender bender, or worse. ABS systems also provide a welcome assistance on icy roads and slick, rainy days.