An air brake system which uses foundation drum brakes will have one slack adjuster per brake - two per axle. They'll be located inside the wheel well - the slack adjuster is will be located at the end of the pushrod which extends out from the brake chamber.
slack adjuster is the adjuster on the brakes of vehicles with air brakes. these are used to adjust and take the slack out of the brakes caused by usual wear on the brakes
attached to the s cams in the brakes. to adjust the brakes.
attached to the s cams in the brakes. to adjust the brakes.
With the brakes applied, the angle of the slack adjuster and the actuating rod should be at 90 degrees.
Assuming we are talking about "S" cam air brakes on a truck, check the angle at the end of the slack adjuster to the actuator rod coming out of the air brake can when brakes are applied, it should be 90 degrees, if the slack adjuster is manual adjust it with the brakes not applied and then test again. If they are automatic slack adjusters and you do not have 90 degrees with brakes applied it is worn out or not installed correctly.
With the brakes released and either the wheels chocked or the trailer brakes set, you rotate the nut on the slack adjuster until the brake shoes are tight against the drum. Then you back it off 1/4 to 1/2 turn. What tools you need specifically depend on which slack adjuster you have... you could have Bendix, Haldex,, or Wabco Meritor slack adjusters.
slack adjusters are part of the brakes. they are ocated on the axle next to each wheel. they are used to adjust the brakes,or to take the slack out on the lickages so as the brakes do not have accesive travel when applied The slack adjuster is the link between the operating rod in the brake chamber and either the S-cam (if you have drum brakes, which is what most of us have) or the power screw (if you have disc brakes) on an air brake system. The "adjuster" part is because the friction material wears out, and you've got to make the linkage longer as it does so the truck will stop properly. (Slack adjusters have been automatic for a long time now.) In operation: you step on the brakes, or you pull the brake valves on the dashboard. The operating rod pushes out, which pushes the slack adjuster, which turns the S-cam, which pushes the brake shoes apart and stops your truck.
I worked for a year and a half as a contractor Carmen on the bnsf. A slack adjuster is a threaed rod with adjusting nuts on the threaed portion that can adjust for proper tension on the brake rigging with includes rods and a chain and an air billow and brake shoes pressing up against the wheel.this slack adjuster must be properly adjusted for the brakes to work correctly.
You'll need either a brake adjustment tool or a wrench (usually 9/16th) to rotate the nut which links to the slack adjuster. Depending on exactly what brake system you have, you may also need tools to either push in or pull out the mechanism which locks the slack adjuster in place. Rotate the slack adjuster clockwise until it locks all the way down, then rotate the wrench/brake adjustment tool counterclockwise two full turns to back the brakes off of the drum.
Poor adjustment, excessive use, worn shoes and/or drums, bad slack adjuster and/or brake chamber (if equipped with air brakes).
Volvos have automatic slack adjusters, which are dangerous to manually adjust. If your brakes are so far out of whack you think you might have to screw with the slack adjusters, you really need a brake job. Usually the slack adjuster must be backed off before you can remount the brake drums. The do have to be adjusted manually to get at least some drag on the drums before you set them automatically.
Remove the cotter pin and pin connecting the slack adjuster to the brake chamber, remove the locking ring on the inside which presses the slack adjuster to the s-cam, slide (or hammer) it out. Installation is opposite of reverse.