When the last foot counts

How many times have you screeched to a stop just feet or inches from hitting another car or object? What would have happened if your car had gone five more feet? A typical stopping distance at 50 mph is 125 feet. Initially, hearing that your car now needs 130 feet to stop seems inconsequential – but is it? How important would it be for your teenager?

Many people are unclear about what the Anti-lock Braking System (or ABS) is, and what it does. You may remember seeing the orange ABS light come on each time you start your car, and turn off a few seconds later. Eventually some cars will experience a part failure that causes the ABS light to remain on all of the time. What’s it all about?

The ABS system is part of the braking system. During normal stopping situations it does not activate and is not involved with stopping the car. The ABS system continuously monitors the speed of each tire. If one or more of the tires skids during braking or turning, the ABS system will instantly become involved. Modern ABS systems instantly adjust the hydraulic braking pressure to each tire to achieve maximum braking without allowing a tire to skid. If one or more tires were to begin skidding the car could loose the ability to steer to avoid an accident. The overall stopping distance could also increase.

If the ABS light comes on you do not need to worry whether your car will stop. The ABS system is a fail safe system – that is when it fails it is still safe. The ABS light comes on when the dedicated ABS computer cannot guarantee that the system is capable of working perfectly. If it cannot be sure, it disables the ABS system and turns on the light.

The normal braking system in the car remains unaffected by the ABS system being disabled. Your car will stop exactly as it usually does, except in panic braking or skidding situations. All you loose is the last few feet of stopping distance.

More expensive vehicles enhance the utility of the ABS system by incorporating a Traction Control System. This system uses the same sensors, computers, and hydraulic system of the ABS system. The TCS adds additional computer programming and upgrades the hydraulic control features. On the newest cars the TCS system also takes over control of the gas pedal.

When the TCS system detects that the vehicle is spinning one wheel on ice or water the system gently applies the brake to that one wheel. More sophisticated systems also sense when the vehicle is about to loose control in cornering. Those systems take over complete control of the gas pedal and braking efforts to attempt to regain control.

Is the ABS system expensive to repair? Not necessarily. In our experience roughly 80% of ABS repairs involve a wheel speed sensor. The total cost of the repair including diagnostics, parts and labor is frequently less than $200. Sometimes the failure is a bad control module. This can cost between $500 and $1,000. Least frequently the hydraulic unit itself is at fault. This is usually $1,000 to $1,500.

Brian Klaubert owns Christian Brothers Automotive – Hamilton Mill, on Braselton Hwy in Dacula. They are “Best of Gwinnett” winners in both the Gwinnett Daily Post and Gwinnett Magazine.