When we encounter trucks on the road, we usually find that they all make a “poof” exhaust sound when they brake. This is the sound of the truck air brake system working.
Our common freight trucks and tractors usually use air brakes, while almost all family cars use hydraulic brakes. Why use different types of brakes? You need to know these useful knowledge. Please continue reading, this article will tell you:
Why do trucks use air brakes?
How truck air brakes work.
How does air brakes work on a truck?
How to apply the brakes correctly when driving a truck?
Why do Trucks Use Air Brakes?
As we mentioned earlier, trucks usually use air brakes, while family cars use hydraulic brakes. What is the reason?
First of all, the most important reason why trucks use air brakes is that air brakes are more powerful than oil brakes. As a vehicle used to transport heavy goods, trucks usually tow semi-trailers weighing tens to hundreds of tons. Then, to stop such a heavy truck at high speed, the braking force required is very large.
The vacuum booster of a family car can only provide half an atmospheric pressure at most, while the air brake uses gas as a driving medium. When the air pressure of the truck’s air tank reaches the required pressure value for braking, step on the brake pedal to brake. The brake sensitivity of Air brake is high and the response is fast, and the pressure on the brake shoes is large. Due to the high inertia of the truck, the truck is more suitable for using air brakes.
How Air Brakes Work?
Air brakes are common on heavy trucks. When the driver depresses the brake pedal, the push rod of the brake cylinder is pushed forward. By adjusting the rear handle, the camshaft is rotated at an angle, and friction is generated at the same time, so as to achieve the effect of braking.
Truck air brake system consists of air compressor, air storage tank, brake pump, quick release valve, relay valve, brake cylinder, adjusting back, cam, brake shoe and other components. When braking, the air pump will compress the air into high-pressure gas through the transmission of engine power, and finally store it in the air storage tank, one of which is connected to the master cylinder.
How do Truck Air Brakes Work?
When the driver depresses the brake pedal, the upper air chamber of the truck air brakes will be opened first, and the high-pressure gas in the air storage tank will be delivered to the relay valve to push out the control piston of the relay valve. At this time, the gas in the air storage tank can be connected with the brake cylinder, and the push rod of the brake cylinder will push forward to make the truck achieve the braking effect.
When the upper chamber of the truck air brakes master brake cylinder opens, the lower chamber will also open. High-pressure gas enters the quick release valve and is distributed to the brake cylinders of the two front wheels. Generally speaking, the rear wheels are braked first, and the front wheels are then braked. As a large truck that often carries hundreds of tons, the truck air brake system used for braking is quite complicated. It must not only ensure the effectiveness of the brakes and ensure safety during transportation, but also be able to cope with various harsh driving environments.
How a Truck Brakes Properly?
Finally, let’s take a look at how to apply the brakes correctly. Braking is the most commonly used function on trucks, and many people don’t pay attention to it. In fact, this is not right. The seemingly simple braking action also has a lot of attention. Correct stepping on the brakes can not only reduce the occurrence of safety accidents, but also reduce the fuel consumption of trucks.
- Determine how hard you step on the brakes. The intensity of stepping on the brakes should be from light to heavy first, and then from heavy to light. In this process, you must learn to control the intensity to ensure that the brakes of the truck can be completed correctly.
- Don’t step on the brake frequently. Because frequent braking will cause unnecessary traffic accidents, keep driving at a constant speed on the highway.
- When braking on a downhill road, you must shift to a lower gear in advance. Because the speed of the car on the downhill road is very fast, for the sake of traffic safety, it is necessary to shift to a low gear in advance on the downhill road, control the strength of the brakes, lightly step on the brakes and keep it, and the strength of the brakes should change from light to heavy, and then from heavy to light.
- In the process of emergency braking, be careful to lightly step on the brake pedal. Step on half the distance of the brake pedal and continue to keep it. During the braking process, if the speed slows down significantly, you can step down slowly.
In general, the structure of the truck air brake system is very complicated, and a simple understanding of the relevant knowledge about truck air brakes will definitely help your driving. Using the correct braking method can reduce accidents and save fuel. If you have comments and suggestions for this article or other questions about the truck, please let us know. We will be happy to answer your questions.