When I was reading a few articles online about the brakes in a car, I came across the term engine brake. Having never heard of something like this before, I decided to conduct a few more searches in order to find out what exactly an engine brake is and how it is used.
What is an engine brake? An engine brake is a system that uses the forces within the engine of a vehicle in order to slow it down, instead of using braking movements like friction or magnetic brakes that would usually be used in this circumstance. Engine brakes are usually found in large commercial vehicles such as semi-trucks, and will make a loud screeching noise when put to use.
If you have ever driven next to a large semi-truck and heard the loud squeaking noises when it reached the stoplight, you might not have realized exactly why those sounds were happening. Most people are unaware of the special braking system that exists within these types of vehicles, called engine brakes.
In this article, we will be covering everything that you need to know about engine brakes, from a description of what they are to how they are used and much more. Keep reading to get all of the details on the topic.
What Is An Engine Brake?
When it comes to vehicles such as cars and trucks, there are usually only two different types of braking systems and mechanisms that are brought up: disk and drum brakes.
While it is true that these are the most common variations of brakes in compact vehicles, how do the larger commercial grade trucks stop their wheels while they are driving? These types of automobiles certainly couldn’t be controlled by the same system as a tiny car, right?
The specific braking system that is found in big trucks is called an engine brake. This is very different from a smaller set of brakes, due to the method in which it stops the vehicle and the process that it goes through in order to do so.
A comparison between these two braking systems is something that we will get into later in this article, but for now we will discuss the characteristics of engine brakes. You can find some of the main points of this concept in the list down below, with a more detailed explanation to follow.
Engine Brakes:
- Found in large commercial vehicles
- Used for stopping the vehicle through the engine’s power instead of through normal braking process
- Utilize a system of releasing air and intaking power to apply braking pressure to the wheels
- Apply a lot of pressure without much work on the driver’s end
As previously mentioned, engine brakes are usually found in large commercial vehicles. However, the difference lies in the way that these types of systems are able to stop the wheels on the vehicle.
Instead of going through a more mechanical process, engine brakes stop the vehicle through the engine’s power. More specifically, the process involves using a system of releasing air and intaking power at the same time in order to apply braking pressure to the wheels.
This system allows the driver to put a lot of pressure onto the wheels without much work on their end, which can be helpful in these types of situations. Keep reading to the next section for a more in depth description of how engine brakes work.
How Do Engine Brakes Work?
Now that you have a basic understanding of what engine brakes are, we will go more into detail about how they actually work to stop the vehicle. In the list down below, you will find some of the main characteristics of this process.
How Engine Brakes Work:
- Releases compressed air from the cylinder of the brakes
- Absorbs power from the engine to slow down the vehicle until it stops
When the driver of a big truck pushes down on the engine brakes, it will release compressed air from the cylinder of the brakes, allowing it to flow into the system.
While this is happening, the engine brakes are absorbing power from the actual engine in order to slowly take away speed and force from the entire vehicle. As a result, the wheels of the truck will begin to slow down gradually until they are able to come to a complete stop.
The dragging process that this type of system goes through is what causes the squeaking noises that you might hear when you are driving alongside a semi-truck on the freeway.
The Advantages Of Engine Brakes
When it comes to driving a very large commercial vehicle, such as the semi-truck that was mentioned previously, engine brakes can actually be very helpful in more than one way.
In this section, we will be outlining the advantages of using engine brakes in these types of vehicles. Take a look at the list below to get a good idea of what some of the positives are in these scenarios.
Advantages Of Engine Brakes:
- Prevent brake overheating
- Convenience (slows vehicle without much effort from the driver)
First of all, engine brakes prevent the brakes from overheating in large commercial vehicles.
If this type of truck were to use a regular braking system that could be found in a compact vehicle, the friction caused by all of the weight would quickly cause the system to get hot and incur damage quickly.
With a larger braking system comes an easier process. This is proven through the convenience that the driver enjoys while using this kind of braking system.
Instead of applying endless pressure to the brakes to try to stop a vehicle that weighs thousands of pounds, the power from the engine will be slowly drawn out until the wheels stop turning, with little to no strength required.
Engine Brakes Vs Regular Braking Systems
Now that you have gotten a better understanding of what engine brakes are, how they are used, and how they can be beneficial in large vehicles, you might be wondering how you can connect the similarities between these systems and the ones that you can find in a more compact car.
When it comes to the brakes in a car, there are two main types of systems. However, the most common one that you will most likely see on the road in the current day is called a disk braking system.
In this section, we will be comparing and contrasting the processes of disk braking and engine braking to give you a more detailed explanation of the latter.
Disk Brakes:
- Release brake fluid through the system
- Fluid applies pressure to rotor
- Rotor creates friction with brake pads, causing the wheels to stop moving
- Engine Brakes:
- Releases compressed air through the system
- Draws power from the actual engine of the vehicle
- Continues to subtract power and force until wheels stop moving
As you can see, there are a few similarities between the disk brakes in a car and the engine brakes in a commercial vehicle. While both of them will release a certain substance through the braking system, from brake fluid to compressed air, they will complete different tasks before being able to stop the vehicle completely.
The process of disk braking includes the brake fluid applying pressure to the rotor until it comes into direct contact with the brake pads, causing enough friction to stop the wheels.
Engine braking, on the other hand, uses the compressed air that it releases in order to draw power away from the vehicle’s engine until it stops moving altogether.
