The brake pedal feel on a vehicle with an ABS system has a very different feel than that of a conventional braking system. When the ABS system is active, you can feel small bumps, followed by rapid pedal pulsations that will continue until the vehicle comes to a stop or the ABS system turns off.

Even though this is normal operation some drivers may think that a serious defect is present in the brake system. Chances are when they road tested the vehicle before they bought it they did not try panic stops. Also the fact that emergency braking can be rare motorists could possibly drive a vehicle for years without using the ABS function.

Note that these pulsations are the result of the hydraulic fluid modulation that is controlled by the ABS computer and the hydraulic braking system. Some of the latest ABS braking systems are starting to use dampening valves in their modulation unit. This reduces the harsh brake pedal feel to the driver’s foot during a panic stop.

what if the driver is complaining about the way the pedal feels when the system is active. The best bet would be to compare the operation with a similar vehicle.

Why we need antilock brakes

With all the problems that come with an antilock brake system such as ABS warning lights being turned on, harsh feel from the brake pedal, why should we have these systems on our vehicles at all?

The goal is stopping the car in the shortest distance possible. In the old days people would have to pump their own brake pedal in a emergency braking situation. Now we have antilock brake systems that can modulate the pressure to the brakes as often as 15 times per second. Friction beetween the road and the tires is enhanced by the pulsation of hydraulic brake fluid allowing the vehicle to stop safely.

Steering is another important consideration of tires that are locked and skidding. Therefore one of the big advantages of ABS is the ability to keep control of the vehicle under these panic conditions. If your front tires are not locked up. You will be able to steer the vehicle away from trouble.

Some people are not aware that antilock brake systems do not prevent all wheel lockups. A small amount of wheel lock is necessary for the shortest stopping distance. During ABS operation, there is a target slip rate that can be anywhere from zero to 30%. This is why when the system is active you can still hear just a slight amount of tire lock up.

The antilock braking system is our friend. Automobiles stop in much shorter distances then cars built just a few years ago thanks to these Abs sytems. Many car owners will drive around with ABS warning light on due to concerns of auto repair costs.

The diagnosis and repair of the Antilock light should be priority one for maintain braking safety. Some ABS malfunctions are easily repaired, such as defective wheel speed sensors. In rare cases, antilock brake system electrical circuit malfunctions can be harder to repair and diagnose.

Tags: ABS brakes, abs light, ABS system, brake pedal feel, computer abs

This entry was posted on Thursday, July 23rd, 2009 at 3:07 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.