What Exactly is Antilock Brakes in a Car?
ABS stands for Antilock Braking System (antilock brakes). This system prevents your brakes from locking up, providing better control while braking.
Tire selection also matters greatly!
by Mr. Nelson | January 27, 2022
Antilock Braking System Overview
ABS brakes do what the name implies – they keep your brakes from locking up while braking. Why? Because once tires start to skid, vehicle control is lost. Therefore, Antilock brakes can help you to maintain more control of your vehicle, particularly while braking and turning or swerving at the same time. In normal driving conditions, ABS systems can also help you stop in a shorter distance, but not 100% of the time. There are situations where you will want to deactivate ABS.
There are four statistical benefits of having ABS:
- Cars fitted with ABS are less likely to be involved in a fatal crash.
- ABS decreases the chance of front-end collision on wet and dry roads.
- Cars with ABS maintain more control while braking – especially through turns, swerves or in variable conditions.
- During an emergency stop, a car with ABS tends to stop in a shorter distance than a vehicle without ABS.
A technician services ABS brakes.
If your ABS light stays on, something isn’t working in the system. Make the safe choice to have a technician fix the problem immediately.
How Do ABS Brakes Work?
ABS uses sensors attached to the hub of each wheel that detect if a wheel is spinning or not, which tells the system the wheel is starting to lock up. As that happens, a modulator slightly releases the brake pad pressure on that particular wheel, allowing it to continue rolling.
Modern ABS systems are linked to the vehicle’s onboard computer and have become increasingly responsive and effective. These systems don’t just keep wheels from locking up during braking, they also alter the front-to-rear brake bias and can prevent losing control under a oversteer situation. Depending on specific capabilities, this latter system is known as electronic brake distribution, traction control system, emergency brake assist or even electronic stability control (ESC).
ABS monitors the brake on each wheel. If it detects a wheel is locking up, it releases that brake slightly to prevent skidding.
Does ABS Improve Safety?
Absolutely! We all know decades before ABS was available it wasn’t uncommon to hear a car with locked brakes skidding out of control. Anti-lock reduced this saving untold lives and property. Locking up brakes was never beneficial but we had to wait for the technology.
This is true on most, but especially on slick roads. But Icy roads when you are in low speed situations in freezing conditions ABS can cause you to slip more. More on that later.
Second, a wheel can only turn a car if it’s rolling. Once the tires begin to skid, the vehicle will continue to travel in a straight line regardless of how the wheels are turned. This is a recipe for an accident, especially when a driver needs to swerve to avoid another vehicle or object. If the tires continue to roll, the driver can keep maneuvering the vehicle, even while braking hard.
Antilock Brakes can also be a huge safety feature on roads with variable conditions. For example, if you’re driving on a road with patches of black ice and you apply the brakes, tires touching dry pavement may grip while tires on ice may begin to slide. This can create a yaw torque throughout the entire vehicle that can put you into a spin.
But if you have proper snow (winter) tires on and you notice at intersections the ABS seems to make you launch further than you intended try disabling it. One issue I have read other say the same thing backing this up is snow tires do need more delay to dig in. With ABS especially on less sophisticated systems, the oscillations may actually cause the skid on the ice to slide further. I have tested this out on both Ford and Volkswagens from 2005-2016. The wiping action of the snow/ice tires seems to want to dig in more.. Test it in a parking lot and you’ll see!
Modern ABS with electronic stability control will help immensely in this scenario. With ESC, the yaw rate of the car and relative slip of each wheel is measured. Adjustments are made by reducing brake pressure slightly on wheels that have the most grip to reduce yaw torque and maintain vehicle control.
Instead, much like a sled, friction between the tires and the road is reduced once the tires begin to slide. Therefore, tires hold the road best when they are rolling.
How Effective Are Antilock Brakes?
ABS brakes are highly effective, but they do have some limitations. In fact, a highly skilled driver can outperform ABS in some driving conditions, such as loose gravel or snow.
That’s because with ABS the brakes are rapidly engaging and disengaging. On very soft or slippery surfaces, the tires simply go from sliding, to rolling, to sliding and back again. Therefore, a driver who practices threshold braking, applying the brakes as much as possible without allowing the tires to slide, can outperform ABS in these conditions. However, threshold braking takes practice and feel to achieve, especially in a panic situation.
And when you’re driving in winter, always allow yourself a lot of extra time to stop.
It’s worth noting, even on snowy or icy roads, antilock brakes can at times improve control while braking hard assuming it’s got a good amount of weight on the tires. Lighter cars may find that ABS should be disabled.. Please research “Will ABS help me in ICE or shoudl I disable?” more on this topic especially via forums!
You can work around most antilock brakes shortcomings by following a simple rule: the softer the surface, the softer you brake. Brake hard on pavement, brake gently on snow or ice.
How Do I Know if My Car Has ABS?
ABS has been a standard feature since 2012, so you probably have it. You can check by looking for an ABS light at startup in the gauge cluster. The ABS light will come on while the system is checked and then turn off. If you don’t see it there, you can always check your owner’s manual to make sure.
The ABS light will come on while the system is checked and then turn off.
What if My ABS Light Stays On?
The ABS light should come on briefly when you start your car, then turn off. If the light stays on, that means something isn’t working in the system. Common antilock brake problems include low brake fluid and ABS or ECU sensors.
If you’re driving when the light comes on you can continue to your destination with caution. The hydraulic portion of the brakes will (and MUST) work without this passive system. However, get it checked out when you can if it’s not a beater. It’s the safe choice and some insurance policies will deny accident payouts if they establish the ABS system was inoperable at the time of the crash. (That’s why I drive cars that are past being worth anything. Saves a lot of money but that’s another topic – I know people like to have shiny things).
If the brake-warning light also comes on, don’t risk losing your brakes completely. Stop immediately and call for roadside assistance.
Antilock Brakes History
Like all technologies, ABS brakes have become more sophisticated and effective over time. Interestingly, the concept for ABS brakes has been around for more than a century. Here is a brief timeline of their development.
1908: J.E. Francis invents a “Slip Prevention Regulator for Rail Vehicles.”
1920: French automobile and aviation pioneer Gabriel Voisin experiments with systems to modulate hydraulic braking pressure on his aircraft brakes.
1958: Road Research Laboratory tests the Maxaret anti-lock brake system on the Royal Enfield Super Meteor motorcycle. Although stopping distances were reduced in most tests, it was not put into production.
1966: Jensen Motors releases the Jensen FF, the world’s first car with a fully mechanical ABS system and all-wheel drive. Shortly after, Ford introduces an experimental Zodiac with mechanical ABS, but the system proved too expensive and ineffective for production.
1969: A fully electronic anti-lock braking system is developed for the Concorde airplane.
1971: Mario Palazzetti of the Fiat Research Center develops “Antiskid,” the first modern ABS system for automobiles. The patent was sold to Bosch who renamed it ABS.
1970s: antilock brakes remain an uncommon feature for most mass-market cars. Robert Bosch acquires patents and begins a joint development venture with Mercedes-Benz. Many of the era’s advancements debuted on Mercedes-Benz cars.
1980s: BMW leads ABS development for motorcycles like the K100.
2012: Electronic stability control, which includes ABS and traction control, are required on all vehicles although many had it 10 or more years prior. My 2002 Mini Cooper had it and did help!
ABS – Can you Dig It?
ABS keeps your brakes from locking up while braking. In so doing, the system decreases the number of fatal crashes and front-end collisions on wet and dry roads. Cars with ABS maintain more control while braking, especially through turns, swerves or on variable conditions. And, especially during a panicked situation, ABS usually helps drivers stop in a shorter distance. ABS is an automobile technology that makes us all safer on the roads, and we can all be grateful for that.
Bleed Brake Fluid that Lasts Longer?
Amsoil’s various fluid choices are synthetic so they tend to handle heat and moisture better. However, we do not recommend extended drain intervals on brake fluid. Lasting longer means it will perform better as the typical abuse adds up which is what you want!! So get 3 or 4 bottles of AMSOIL DOT 3 & 4 and flush you brakes.
And while you’re at it get our hard to find Brake Parts Cleaner (hard to find a true chlorinated version in the parts stores these days – not for sale in California) It’s actually very low cost!
_by Keith Montgomery|October 25, 2023
