How Do Air Brakes Work - Ultimate Truckers Guide

How Do Air Brakes Work – Ultimate Truckers Guide

In this article, you’ll learn how do Air brakes work, what are their components and how they work, and why Air brakes are a crucial component and a MUST for heavy vehicles and trucks?

First then all, welcome to the world of Air brakes! It’s a wonderful world as long as you know what Air brakes are and how do Air brakes work!

And if you don’t, then the outcome is not scary, it’s terrifying! But I will tell you some more about this latter, now let me concentrate on presenting you the ultimate truckers guide on how do Air brakes work?

Source: Youtube

Truck Air brakes, spring brakes and all different types of brake systems are designed to give you the best stopping assistance possible. They are durable, sturdy, well built equipment that is a crucial part of every motor vehicle, especially when it comes to class 8 trucks.

The average truck weighs several pounds. If you add a heavy load on top of that, it can take a lot to stop, don’t you think? That’s why; you should never underestimate the importance of your Airbrakes!

When you are preparing to take your Air brake test, study and practice well.  Yes you read me well! The Federal Motor Carrier Safety Administration (FMCSA), require testing to ensure both driver and company are in compliance with safety related rules and regulations.


So, don’t just go through the motions. Study for your CDL test and Air brake test! Because believe me when I am say, there will be a time when you will remember my words!

It will be a time when slamming on the trucks’ Air brakes is all you will do! You just didn’t yet have that route through the Rocky Mountains or some of the other dangerous roads out here!

History of Air Brakes and 101 Lesson On What Are Air Brakes?

So, I named this article “How do Airbrakes work”, and I will try to come as close as I can and explain more than just the bare basics of an Airbrake system and how do Air brakes work!


But, first things first, and before I even start with how do Air brakes work, I will give you few words on history of the Air brakes and move along from there.

Before the Air brakes were born, the trains, buses and tractor trailers were using a primitive brake system.

For example the train break system was requiring an operator, or brakeman, in each car who will be there to apply a hand brake every time a signal was given from the train director/engineer! Can you imagine that hustle?

Of course you can’t! – Neither do I! But it was that way there for a while, until this inefficient manual system was replaced by direct Air brake systems.


These direct Air brake systems were using an air compressor to feed air through a brake pipe into the air tanks of each car.  Then if/ when the engineer will apply the brakes, the pipe was filling inside with air and squeezing the brakes.

Later on, in 1869 to be exact, the engineer named George Westinghouse invented the first triple-valve Airbrake system for railcar use. His system was working in the opposite way from the previous direct Airbrake system, and performed three functions as its name is implies.

The triple –valve Airbrake system main functions are:

  • Charging;
  • Applying; and
  • Releasing.


The system must be filled with air before the brakes will release. Even though the brakes remain engaged at rest, as soon as the system reaches its operating pressure, and the brakes are ready to use.


The air pressure decreases when the brakes are applied.  When the air decreases, the valve allows air back into the reservoir tanks and the brakes move to the applied position.


When you apply the brakes, the air will escape after braking, and all that pressure will release the brakes. In order to release the brakes, the triple-valve system fills a supply tank and uses air pressure. So, the brakes in a triple-valve system remain fully engaged until air is pumped throughout the system.

Where Are They Used?

I can’t stress enough the importance of the Air Brake systems. They are one of the most important truck equipment.


It is ok to not have the best truck tires on the market! You might not need a custom made trucker hat to drive the dry van trailer you wanted. Heck, you don’t even need a perfect truck driving resume to land the local driving job near you that you desperately wanted!

But imagine that you just landed a driving position with one of the top 25 car transportation trucking companies that transport those one of kind vehicles or some rare, vintage trucks and cars!


Hey! I'm George J.Magoci and I will send you a FREE eBook where you can learn 12 secret steps how to make $950 more truck/month.

Free ebook

And it’s all good and great except the fact that your Air brake skills are limited, and you end up ruining what could really have been one of a kind!!!

I can’t even imagine the above scenario, but that is neither here nor there. What is important right now is to bring to your attention the importance of the Air brakes, where are they used and the detailed explanation of how do Air brakes work!


In addition, let me say a word of two about the use of Air brakes in the overall automotive industry.

So, as we said, Air brakes are used in trucks, buses, trailers and semi trailers. There are several reasons why this brake is the preferred type of braking system for these vehicles.

First and most important reason for these heavy-duty vehicles to use Air brake instead of hydraulic brakes is the fact that the use of air allows multiple vehicle units to be coupled. This way all units have braking capability and can be controlled from the cabin.



< Page 1 / 4 >