Automatic Slack Adjusters have become a standard part on heavy duty truck vehicles. In 1994, it became required by the U.S. Federal Motor Vehicle Safety Standard to have them on your vehicles. But that doesn’t mean all slack adjusters are made equal. There are two significant types of automatic slack adjusters, Stroke Sensing and Clearance Sensing, and it’s important to know which one is which.
What’s The Difference?
The difference is in the measurement. A slack adjuster on the surface is just a measuring tool that tells you how much give there is between the push of the brake pedal and where the brakes are applied. But there are two places that you can measure the effectiveness of a brake, the stroke of the brake being applied by the driver, or the clearance between the brake pad and the drum after the brake has been applied.