On the simplest of terms, brakes are easy to understand. When you apply brakes, they help slow you down. Keep applying pressure and eventually, you’ll come to a complete stop.
Everything in motion uses some type of braking system. You’ll find it on heavy machinery, airplanes, bicycles, and of course, cars.
Depending on how old your car is, and how familiar you are with automotive history, you might be familiar with two types of braking systems on a car: power brakes and anti-lock brakes. What’s the difference? Why does it matter? And is one more preferable over the other?
Before we dive into that, let’s look a little deeper into how the braking system works.
How brakes on today’s cars work
If you want to slow down or come to a stop, you apply pressure to the brake pedal, and it goes into action. But while you can feel the motion taking place, a lot more is going on than you can see.
The brake pedal is connected to a rod that connects to the vehicle’s master cylinder, which is then bolted to a firewall. If you have power brakes, this rod is first bolted to a vacuum booster, which is then connected to the firewall.
This rod works as a piston inside the master cylinder. When the rod is pushed into place, it forces brake fluid through the lines. This creates action at the brake caliper level, which forces brake pads against the brake rotors, which slows the vehicle down. It’s the friction of this process, the connection between the brake pad and the brake rotor on the wheel that makes the vehicle slow down.
Understanding power brakes
If you went back in time, the braking process was rudimentary at best. Todays’ brakes are built around Pascal’s law of hydraulics, which is the law of fluids in motion and how they can be used to increase force. Pascal’s law states that when there is an increase in pressure at any point in confined fluid, there is an equal increase in pressure at every point inside the container.
That law has been transferred many times as the modern day braking system was designed and refined.
Power brakes were initially developed for heavy vehicles during WWII. It made this machinery easier to slow down and stop.
An engine naturally generates a great deal of vacuum. The concept of power brakes is designed to siphon off some of that power, and store it in a booster that is created to help with the braking process. By stepping on the brake pedal, this vacuum multiplies the effort your foot puts towards the pedal, making the entire braking process easier, with more power.
Vacuum boost power brakes became by far the most popular type of assisted brakes. That’s because it puts more power throughout the application of brake fluid, and less effort from the operator. It’s a simple system that’s reliable at the same time.
But of course, through invention and ingenuity, there is always room for improvement.
Understanding anti-lock brakes
Even as an experienced driver, there are times when your reaction speed doesn’t match the level of intensity you’re experiencing. You have to make split-decisions in order to keep your vehicle safe and on the road.
Accidents occur. And that made inventors go back to the drawing board, looking for ways to improve on the power brake system.
Even as an experienced driver, if something jumps out in front of you, or you face immediate danger, the natural reaction is to find yourself jumping on the brake pedal.
This is how anti-lock brakes, or ABS, were developed. It’s designed to prevent the wheels from locking up, which helps keep a grip on the road.
Anti-lock was first created for aircraft back in the 1950s. Sensors were used to monitor the rotational speed of each wheel, and send it in real time back to a processor. This processor controls a series of valves that meter the braking effort and force level used at each wheel. If one wheel slows down more than the others, or is on the verge of locking up and skidding, the processor reduces the hydraulic pressure in that brake line to stop the situation from happening. This works exceptionally well on wet pavement, where the car can go into a dangerous skid.
ABS reduces the risk of skidding even when you, the driver, faces excessive potential problems. Your instinct is to stop the car as quickly as possible, but with ABS, it judges how to do so safely given the current conditions. That is why it’s important to leave ample distance around you to allow ABS to do its job. Cars with ABS:
- Are less likely to be in fatal accidents
- Are less likely to have frontal collisions on wet or dry roads
That is why they are a standard feature on all of today’s vehicles.
Ensure your anti-lock brakes work through regular maintenance
Anti-lock brakes are designed to be there when you need them most. That means they require occasional maintenance to ensure they keep working their best.
One of the simplest steps you can take is by keeping your car clean. Brakes that are dirty, caked with oil and grime, can’t function how they were designed. Occasional washes are a good way to keep your car looking great and running equally as well.
You should also avoid overusing your anti-lock braking system. ABS isn’t something that was designed for daily use. The more aggressively you drive, the more chances you take while out on the road. Drive with care. Stay back from the vehicles in front of you so you have more time to react. Take extra care if the driving conditions change. Stay off the roads if you can avoid it in inclement weather.
You may also need to have the ABS speed sensors calibrated from time to time. Over time, they can become misaligned. One of our experienced mechanics can access the computer system at different speeds to reset and calibrate each sensor at each wheel. This should be done yearly, or any time you have maintenance work performed on your braking system.
Let’s talk a bit about how anti-lock brakes work. If you think back to your lessons in drivers ed, you might remember how they taught you to take control over your car if you hit a patch of ice. If the brakes won’t work and you slide, pump the brakes instead by pressing down on the brake pedal and letting go, over and over again. This helps your tires look for traction instead of continuing to slide.