Why are anti-lock brakes an important part of the modern automobile and a feature found on everything from compact cars to heavy-duty trucks? They contribute greatly to vehicle safety and driving performance. From preventing vehicle skids to providing better dynamic control, there are several important benefits of this technology. Anyone behind the wheel – whether a professional or a rookie – can benefit from knowing exactly what anti-lock brakes are and why they are so important.
What Are Anti-Lock Brakes?
Fundamentally, an anti-lock braking system (ABS), functions by preventing the wheels of the vehicle from locking up when breaking in slippery or emergency situations. A wheel would lock up if the breaking force was too big, causing the wheels of the vehicle to stop spinning whilst the vehicle is still in motion. This could lead to dangerous skidding, loss of steering control and long braking distances.
In the ABS system, brake pressure to each wheel is automatically modulated in order to keep the tyres from losing traction and locking up (slipping entirely). In addition to keeping the vehicle under control, this allows the driver to steer while braking, a critical factor in avoiding an accident.
How Anti-Lock Brakes Work
The anti-lock brake system relies on several key components to function properly:
Each wheel has a speed sensor on it to measure the rotational speed of the wheel. If the speed sensor sees the speed of a wheel decreasing faster than the others, this is a sign that the wheel will lock up.
Electronic Control Unit (ECU): The ECU is the computer that actually controls the ABS. Its job is to read signals from the speed sensors and decide if the ABS needs to do anything. If the ECU detects wheel lockup, it sends a message to the brake system to reduce pressure.
Hydraulic Valves: The hydraulic valves control the amount of brake fluid pressure applied to each wheel. When the ABS is engaged, these valves open and close rapidly to shave off pressure to keep the wheels from locking up.
ABS Pump: During ABS activation, when the hydraulic valves are reducing the pressure, the pump rebuilds the pressure needed to maintain the braking force, and the car doesn’t end up coasting to a stop.
Specifically, ABS intervenes if it detects wheel lockup by applying and releasing the brakes at an interval of a few times per second in order to maintain grip and allowing the driver to steer away from an obstacle. You might feel the pulsation of the brake pedal to your foot, which is a completely normal feeling indicating that the system is functioning as expected.
Benefits of Anti-Lock Brakes
Improved safety is the major reason for having anti-lock brakes on your vehicle, by preventing the wheels from locking up so you can maintain control of the vehicle. This also allows you to keep driving in an emergency braking situation, and prevents you from skidding and hitting things:
Better steering control: When you hit the brakes hard in an emergency, your wheels might lock up, which can throw your vehicle off course. ABS for vehicles is designed to help you keep steering control, and use it to stay on course and avoid obstacles.
Shorter Stopping Distances: ABS works to shorten stopping distances on slippery or wet road surfaces. Preventing the lockup will keep at least one portion of the tire in contact with the ground.
Improved vehicle stability: ABS is used in conjunction with other systems, such as electronic stability control (ESC), to improve vehicle stability during emergency manoeuvres on loose or slippery surfaces or in conditions of adverse weather, such as rain, snow or ice.
Less Tread Wear: Skidding and locking up your wheels shortens the life of your tyres. ABS stops this in its tracks by maintaining better contact between the tyres and the tarmac and thereby lengthening the life of your tyres.
Adaptability: ABS works unequivocally well on wet or icy roads, but even in the dry, it still brings an element of safety to your daily routine. Modern ABS may also increase braking distances on loose gravel due its regular brake application, but given the overall stability and control provided, it’s a small price to pay for safety. It’s also worth noting that on snow-covered roads, I would level the playing field between ABS and no ABS, with both systems being equally efficient.
Common Misconceptions About Anti-Lock Brakes
Although these benefits are quite obvious, there are some misconception about anti-lock brakes that could cause confusion:
ABS doesn’t make stopping distances shorter: True, ABS helps to reduce braking distances in most scenarios, but it doesn’t guarantee shorter stopping distances. ABS won’t cure all evils. For example, even though negotiable surfaces such as gravel and snow-covered roads are governed by very different physical principles, their stopping distances are slightly longer when ABS is applied compared with other road surfaces. However, wheel lock-up is prevented allowing better control of the car’s steering.
You don’t have to pump the brakes: This is an important point. Old-school drivers (ie, those drivers who learned to drive before ABS was widespread) were taught to ‘pump’ the brakes when driving in slippery conditions. With ABS, pumping is not useful since the system automatically cycles brake pressure far more efficiently than a human pumping the pedal.
ABS does not prevent all types of accidents neither: Even if ABS reduces crash risks by reducing the chance that the car will skid and that the driver can maintain control in many situations, it does not eliminate risks of accident. Safe driving such as maintaining a proper following distance and driving at appropriate speeds for conditions still required.
Maintenance and Care for Anti-Lock Brakes
Your anti-lock brakes are a component, just like any others, and they also need regular care. You can check out some tips below on how to do it:
Brake Fluid Levels: Keeping the brake fluid in the ABS system at optimal levels means it should be functioning at maximum efficiency; low or contaminated brake fluid can impair the system.
Check the ABS Warning Light: If the ABS warning light illuminates on the dashboard, your system is not working for some reason. There could be an issue with a sensor, the ECU or another cause of failure. Get this checked out, and it will regain functionality again.
Inspect Brake Pads and Rotors: Badly worn brake pads and damaged or warped rotors will lower breaking efficiency which may also affect the functionality of the antilock brakes.
ABS ENABLES PROPER BRAKING ON GOOD TIRES: Keep your tires properly inflated and with adequate tread depth. Worn or under-inflated tires can reduce the effectiveness of ABS.
Conclusion
Anti-lock brakes represent an important safety feature for modern passenger vehicles. In normal braking situations where the vehicle’s maximum braking capabilities are achieved under dry conditions (the wheel’s friction is sufficient enough to meet such requirements), no intervention is necessary. However, in emergency braking situations, wheel lockup is still a potentiality. ABS prevents wheel lockup in these conditions; therefore, it helps reduce the possibility of skidding, improves the vehicle’s steerability, and enhances overall vehicle stability. ABS doesn’t replace safe driving techniques, however, because it just helps drivers avoid risky situations on the road.
Like any vehicle system, the ABS should be maintained regularly so that it works as intended. Keeping the system’s brake fluid topped up, regularly checking tire condition and general brake inspections can help avoid any problems when ABS is needed most.