What is Spring Brake and Slack Adjuster?

Spring brakes are brake chambers that include a powerful spring that acts as a parking brake or an emergency brake. The spring brake system is attached to the service brake, and has its own air supply and diaphragm. The spring brake is activated when air pressure is not applied to the brake chamber, or when the brake system loses air pressure. Spring brakes are a safety feature on trucks and trailers to prevent them from rolling away or crashing.
When the brake lining or brake pad wears, the gap between it and the brake drum increases. Automatic slack adjusters have an adjusting mechanism that adjusts for brake lining wear. However, manual slack adjuster periodically needs to be adjusted to properly function and operate at peak performance