Conventional Brakes vs. ABSConventional Brakes
When a vehicle is equipped with conventional brakes, and you push the brake pedal hard when stopping on loose or slick surfaces, one or more of the wheels may lock up (stop turning). Lock ups can cause the truck to swerve or skid, leaving you with little or no control of the vehicle.
When an anti-lock brake system is present, a sensor in an about-to-be locked up wheel sends a message to a computer. The computer immediately starts releasing and applying that brake, preventing a lock up and allowing you to maintain control -- or drive around an obstacle instead of sliding straight towards it.
When the anti-lock system kicks in, it makes a noise and the brake pedal pulsates. If that happens, don't panic -- keep your foot on the brake pedal and let the anti-lock system go to work. Letting up on the pedal may turn off the ABS.