Learn the functioning process of the air brake chamber
Front air brake chamber
They are connected to an air compressor and basically they are solid steel housings. To each chamber there is a bleed valve and a push rod. Inside the push rod there is a spring return and a pressure plate.
Air from the compressor goes into the chamber and causes push rod to go out with a force of 1000 pounds, when the brake pedal is pressed. At the end of the push rod there is a long rod sitting in the interior of the drum brakes, called an S-cam. This piece pushes the brake shoes against the drum inside of the wheel, causing the wheel to stop. Unlike hydraulic chambers, air pressure is more efficient causing a faster and powerful braking.
Rear air brake chamber
Besides doing the same as the front air brake chambers, they also serve as parking brake. This is a system with two chambers. Besides the already present push rod and air chamber, there is another chamber. Inside this chamber there is a braking spring on solid plate, similar to the one of the push rod. The parking brake lever inside the driver’s cabin connects to this using a latch.