How To: Adjust air brake system slack

This is an "auto slack adjuster" and must only be adjusted by actuating the service brake fully while maintaining a minimum air pressure of 90. This must be done enough times to ensure adjustment is done to ensure adjusters have had enough actuations to take up the slack between the brake linings and drum- this can be up to 10-12 applications.
The adjustment is done on all auto slacks on the return stroke of the push rod...so full on and full off brake applications are required.
You should contact a manufacturer of air brake components....like Rockwell, Gnite or Haldex and they are qualified and capable to address questions on air brakes.