Truck Accident Lawyers

What's 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 electrical cable provides power to the lights and any specialized features of the trailer, such as refrigeration.

There are two air lines that control the trailer’s brakes. The “emergency,” or main, line pressurizes the trailer’s air tank and disengages the emergency brake. The “service” line controls the application of the brakes.

In addition to a complex set of air brakes, 18-wheelers frequently have engine brakes. Engine brakes control the hydraulic actuators on the exhaust valves of a truck’s diesel engine. They hold the valves slightly open which turns makes the engine virtually a compressor. Unfortunately, this produces a loud noise which has caused many cities to ban the use of the engine brake.

Whenever you are on the road, it is important to remember that trucks are large and often quite heavy. Regardless of how good their brake system is, it still will take them a long time to stop.

If you have been in an accident which involved an 18-wheeler and been injured, please contact the truck accident lawyers of Williams Kherkher at 1-866-950-9000 to discuss your case and to determine your legal options.