Whats stopping an 18-wheeler?
18-wheelers travel thousands of miles across the country every day of the week. Their brake system is quite different than that of a regular car. Because they use an air brake rather than a disc, drum, or hydraulic brake system, trucks’ brakes work differently. Trucks use air pressure rather than hydraulic fluid to actuate their brakes. The “emergency brake” of the trailer and the “parking brake” of the tractor are both spring brakes. They require air pressure to be released. The brakes are applied when air pressure is released and disengaged when the air pressure is supplied. The 18-wheeler has two brake systems as an emergency feature. The emergency feature is there to ensure that if air pressure is lost to either piece, the entire unit will not lose all of its ability to brake and become uncontrollable. The trailer controls are coupled to the tractor through two “glad-hand” connectors. One of the connector supplies air pressure and the other provides electrical to the trailer. The e
