Your ABS Brake System: What Does it Do, Exactly?
When learning to drive on slippery surfaces, many of us were taught that we should pump the brakes to prevent going into a skid. Of course, that was before the ABS brake system was commonplace. The modern anti-lock brake system (ABS) was invented in the 1970s and is standard on many models, though it’s interesting to note that you can still find many models without this safety feature.
If you have one of these non-ABS models, keep pumping those brakes! On the other hand, if you drive one of the hundreds of models that are equipped with ABS, here’s a little background on exactly what it is, what it does, and some tips about whether having ABS should affect how you drive.
ABS Brake System Description
Normally, on a good dry road surface, optimal braking occurs when the amount of friction in the brakes is just shy of the amount of friction between the tires and the road. On a slippery road, however, there’s far less friction between the tires and the road, which means that you can’t apply that much friction in the brakes.
This can be a problem if you need to come to a stop quickly. Because the friction in the brakes exceeds that of the tires, you can quickly lock up the brakes, which would put your car into a skid as you lose all traction and steering capability. This is why you were always taught to “pump the brakes,” to keep them from locking up, but as the name implies, the anti-lock brake system keeps your brakes from locking up.
Using wheel speed sensors (WSS), the controller anti-lock brake (CAB) or ABS controller monitors wheel speeds. While braking, if the CAB detects that a wheel is stopping too soon, it releases brake pressure momentarily to keep the wheel from locking up and losing traction. Some ABS systems can pulse the brakes up to 15 times per second. The end result is that the brakes don’t lock up and tires maintain traction with the road, giving you the control needed to safely maneuver or stop.
First, if you are driving a vehicle with ABS, take to heart that this type of safety technology is not a substitute for safe driving habits. In other words, your ABS brake system will not keep you from sliding off the road if you are driving too fast for the conditions. Always give yourself plenty of space to maneuver and brake, even more so at greater speeds or in times of poor road conditions.
Second, when driving a vehicle with ABS, do not pump the brakes — ABS is already doing that for you. You will feel pulsation in the brake pedal and probably hear what sounds like grinding or buzzing from under the hood. You may also see warning lights and hear a warning alarm. Don’t panic, just keep your foot firmly on the brake pedal. Braking distance may or may not be improved, but steering and stopping control will be greatly enhanced.
Perhaps the best way to get used to your ABS brake system is to test it out, preferably in an empty parking lot. That way, you can get a feel for how your vehicle sounds and feels while the system is active and learn to trust that it will do the job as long as you are doing yours.
For more information on your ABS brake system, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Foter