Some facts about an auto necessity: anti-lock brakes
Written by Nick Shultz | | letters@toledofreepress.comThere are many technological enhancements that can be had with today’s high-tech automobiles.
Perhaps the most useful of all the computer-controlled systems available to us are the anti-lock brakes system that comes standard on many new vehicles.
My motorcycle and I have become quite familiar. I ride it so much that I have forgotten how technologically advanced it is. My BMW motorcycle comes standard with anti-lock brakes.
I have become so used to my bike’s braking action and brake feel that I had forgotten what riding a motorcycle without anti-lock brakes was like.
I had the occasion, recently while on a road trip in Tennessee, to ride a friend’s late-model bike that did not come equipped with anti-lock brakes. I discovered in short order what a real disadvantage not having anti-lock brakes can be.
The same is true for our cars. We can become so accustomed to the anti-lock brake feature, we forget how difficult braking was before we had this feature. Many young drivers have never driven a vehicle that did not have the anti-lock braking (ABS) system installed upon them. Please don’t misinterpret my meaning. I believe that’s a good thing. However, unless drivers have operated vehicles during panic situations without ABS, they truly cannot appreciate the remarkable stopping advantage ABS affords them.
Directional stability and stopping distance are the chief reasons ABS systems are so advantageous. ABS insures that all wheels are applying stopping force equally. When one wheel decelerates faster than the others, a vehicle pulls toward the wheel, applying the greatest amount of stopping force. Naturally, this could cause loss of control during a panic stop. ABS prevents this unwanted loss of directional stability from occurring.
Because ABS systems are capable of applying the brakes at a much faster rate than most drivers can actuate the brakes, a significant decrease in the amount of distance an ABS-equipped vehicle can safely stopped is achieved.
When a tire locks up during braking the rubber between the vehicle and the road surface actually begins to melt. The liquefied rubber loses traction and the vehicles stopping distance is greatly reduced. ABS action keeps the tires from ever locking up.
ABS systems are designed specifically for the vehicle they are installed upon. Some systems control the braking on all four wheels, while other ABS systems control the front wheels independently of each other while the rear axle is controlled as a unit. In any ABS system, the vehicle wheel speed sensors are critical.
An ABS controller (computer) monitors individual wheel speed and verifies that each wheel is decelerating at nearly the same rate. When one wheel decelerates at a greater rate than the others, ABS action is initiated.
The ABS module isolates any hydraulic fluid from reaching the wheel which is approaching “lock-up” and if necessary, releases a small of amount of brake fluid from the affected wheel until its deceleration rate coincides with the other wheels.
Most modern ABS systems can perform this function about 14 times within a second. That is much faster than most drivers could ever “pump their brakes.”
And obviously, as mentioned above, this pumping action prevents the tires from losing their coefficient of friction between the vehicle and the roadway. Ultimately this ABS action stops the vehicle in a shorter distance.
Another great feature of modern ABS systems is they only work when we need them. Most braking occurs without the ABS system ever being initiated. ABS only “turns itself on” and performs the ABS braking function when a wheel is approaching lockup.
Another great feature of the latest ABS systems is its ability to prevent a wheel from slipping during acceleration.
This programmed-in ability is referred to as “traction Assist’ by most manufacturers. Basically, instead of controlling wheel slip only during decelerations the ABS computer also controls wheel slip during acceleration.
This is a great feature here in the North Country during the winter months.
If ABS does not come as a standard feature on your next vehicle purchase, I urge you to add it as an option. It is clearly one of those systems that no vehicle should be without!
Nick Shultz is an instructor of Automotive Technologies at Owens Community College. He is an arbitrator for the Better Business Bureau who specializes in cases involving the Ohio and Michigan Lemon laws. He is a certified master automotive technician by ASE, General Motors Corp. and Ford Motor Co. Shultz, a Toledo native, will take questions from letters@toledofreepress.com.
Tags: anti-lock breaks, auto repair
