Slack adjusters are mechanical links between the brake-chamber push rod and the camshaft on cam type brakes. Slack adjusters are not used with wedge-type brakes.
Slack adjusters are used to manually (Fig. 51) or automatically (Fig. 53) maintain proper brake chamber stroke and lining-to-drum clearance during normal operation.
Slack adjusters are available in a variety of arm configurations, lengths, torque ratings and spline types.
The entire slack adjuster operates as a unit, rotating with the brake camshaft as brakes are applied or released. The most efficient braking occurs when push rod travel is held to a minimum, therefore it is important that brake adjustments are made often.