Regardless of chamber size or slack adjuster arm length, adjust the slack mechanism so there is 1/2 in. (12.7 mm) to 3/4 in. (19 mm) of push rod travel when manually (by hand) extended to place the shoes in contact with the drum.

After adjustment, check for brake contact by gently striking the brake drum with a metal hammer. When the brake shoes are away from the drum, a ringing sound will be heard. A dull sound indicates brake drag and that re-adjustment is required until drag is eliminated

Check push rod travel after adjustment

Note: If the brakes can’t be adjusted by either of these two methods, inspect the foundation assembly for worn or broken components.