We rely on trucks every day to deliver various goods from suppliers to retailers or to courier goods to specific destinations. They transport our food, clothing and other supplies that we need and want. Air brakes are often used in larger or heavy duty vehicles. Because air can be found so easily all around, it is easier to use the gases from air to operate the braking systems of trucks and other big vehicles.
In trucks, foundation air brakes are the most common systems found. This system uses the triple valve principle that was originally invented in the late 1800’s. The air fills up inside the brake pipes releasing the brakes.
When the truck is in an idle position, the air pressure will overcome the diaphragm or S-Cam (a cam shaped like an “s” that pushes the brake shoes apart and against the brake drum) into a closed position which will release the brake system. Once you press the brake pedal, air pressure will decrease which will turn the cam, spreading the brakes shoes against the drums.
The compressor will then refill the compressed air tank and will return to its original state when you release the pedal.
Similarly to standard air braking systems are the emergency air brakes found in a truck. The emergency brake is located around the dashboard that needs to be pulled to be engaged. Once you push the emergency brake back the braking system fills with air.
Operating a truck is difficult if you believe that it works the same way as the car you drive every day, you would be mistaken. Most trucks will state that the emergency brake is engaged and needs to be released with a flashing light. If this emergency brake is not released, the truck will stall and lurch forward.
The whole system works similar to the regular brakes on the lightweight vehicles. Every now and then, you will have to take the truck in to get a brake pad replacement as they will get worn. The truck is much larger than regular vehicles which imply that larger and heavier duty pads have to be present in order to stop the vehicle.