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What Your Anti-Lock Brakes Do

ABS can improve vehicle stability, steer ability and stopping capability. Four-wheel ABS prevents wheel lock-up, allowing drivers to maintain stability as well as steering control during an emergency braking situation.

How the Anti-Lock Mechanism Works 

When a driver operating a four-wheel ABS equipped vehicle steps firmly on the brake pedal, the system automatically modulates the brake pressure at all four wheels, adjusting pressure to each wheel independently to prevent wheel lock-up. With four-wheel ABS, the driver has improved steering control of the vehicle.

The Difference between Four-Wheel and Rear-Wheel Anti-Lock Brakes

Four-wheel ABS is designed to maintain vehicle stability and improved steer ability in emergency stopping situations. Because the braking system in a four-wheel anti-lock equipped vehicle modulates the braking pressure, preventing wheel lock on all four wheels, the driver has improved control over steering.

Rear-wheel anti-lock brakes, found exclusively on light trucks, vans and sports utility vehicles, prevent wheel lock of the rear wheels only. This allows the driver to maintain directional stability and prevents the rear end of the vehicle from skidding sideways. The front wheels can still lock up on rear-wheel ABS systems just like conventional brakes. If that happens, the driver should ease up on the brake pedal with just enough pressure to allow the front wheels to start rolling again, so the driver can steer.

How to know when your ABS Is Working 

Most anti-lock brakes let you know when you have activated your ABS. The driver can notice a mechanical sound and feel some pulsation or increased resistance in the brake pedal. It is important to keep your foot on the brake pedal when you hear noise or feel vibrations. Continue to apply firm pressure.

Tips for driving with ABS -Anti-Lock Brake Systems

Always "brake and steer" when using four-wheel anti-lock brakes. With ABS, all you have to do is "brake and steer". With four-wheel ABS, push the brake pedal while steering normally and keep your foot firmly on the brake pedal until the car comes to a complete stop. Don't take your foot off the brake pedal or pump the brakes, because that will disengage the anti-lock system.

Remember that you can steer while you are braking with four-wheel anti-lock brake systems. Steer clear of hazards while keeping your foot firmly on the brake pedal. Be aware that your vehicle will not turn as quickly on a slippery road as it would on a dry road.

Drive safely, because your anti-lock brakes are only as good as the driver using them. Anti-lock brakes cannot compensate for driving faster, more aggressively, or maintaining unsafe following distances. They cannot guarantee recovery from a spin or skid prior to an emergency braking situation. Avoid extreme steering manoeuvres while your anti-lock brake system is engaged.

Expect noise and vibration in the brake pedal when your anti-lock brakes are in use. These sensations tell you the ABS system is working properly.

Anti-lock brake systems can stop more quickly than conventional brakes on wet paved surfaces and on icy or packed snow-covered roads. Stopping distances can be longer on loose gravel or freshly fallen snow, although drivers won't experience the lock-up of the wheels usually associated with conventional hard braking. Therefore, drivers will still have the ability to steer around objects in front of them-such as another car.

Know that there is a difference between four-wheel and rear-wheel ABS. Four-wheel ABS prevents wheel lock on all four wheels giving the driver improved control over steering. Drivers of four-wheel ABS cars should step firmly on the brake in an emergency stopping situation and keep their foot on the pedal.

In light trucks that are equipped with rear-wheel ABS, however, the front wheels can still lock up the same as with conventional brakes. If that happens, the driver should ease up on the brake pedal with just enough pressure to allow the front wheels to roll again so the driver can steer.

It's easy to find out whether your car has anti-lock brakes. To determine if your car has anti-lock brakes, look for an illuminated ABS symbol on your dashboard immediately after starting the engine, check your owner's manual, or ask your dealer. ABS Education Alliance http://www.abs-education.org/

Tips for Driving with ABS -Anti-Lock Brake Systems

RoadDriver Tips and Advice Article No27 2010


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