What is a Jake Brake? – A How-To Guide for Truck Drivers
Have you ever heard a semi-truck make an extremely loud sound while slowing down or coming to a stop? If you have, then you’ve likely heard a Jake Brake in action. But what is a Jake Brake on a truck and what does a Jake Brake do, you ask? A Jake Brake, also known as a compression release engine brake, is a braking mechanism for large diesel engines. Essentially, it’s a way of slowing down the vehicle without having to employ the service brakes. This can be really beneficial in preserving your service brakes, effectively extending their lifetime, and reducing costs since your brakes will require maintenance less often.
So, what is the purpose of a Jake Brake, and how does a Jake Brake work? Read on to learn more about Jake Brakes and tips on how to use them properly.
What Is a Jake Brake?
As briefly mentioned above, a Jake Brake is an engine brake that uses the engine to slow down a semi-truck rather than using the traditional service brakes. In addition to compression brakes, there are actually various types of other brake retarder systems like exhaust brakes and variable-geometry turbo brakes, but the Jacobs Engine Brake (nicknamed the Jake Brake) has become synonymous with engine brakes as a whole.
How Does a Jake Brake Work?
When employed, a Jake Brake opens the exhaust valves on the engine to release the compressed air that is held in the cylinders, hence the alternate name “compression release engine brake”. By releasing this compressed air instead of returning this energy to the crankshaft, effectively slowing the vehicle down and allows the driver to maintain or gain more control.
Jake Brake vs. Exhaust Brake
Although they are both brake retarder systems, Jake Brakes and Exhaust Brakes are essentially opposites in how they function. As you now know, a Jake Brake releases the compressed air that gets trapped in the cylinders. Exhaust brakes, on the other hand, trap the engine’s air within the exhaust system. This creates back pressure that actually forces the engine to rotate more slowly.
While both types of brake systems have their pros and cons, one of the main oppositions to the Jake Brake system is that it is known to be very loud. People often compare it to the sound of a machine gun. Despite the excessive noise, Jake Brakes are very powerful and can be an incredibly useful tool.
Tips For Using a Jake Brake
When using a Jake Brake, there are a couple of key things to keep in mind:
- Jake Brakes are not meant to be used in icy or slippery conditions, so be aware of weather conditions before using your Jake Brake.
- Pay attention to signage as “No Jake Brake” signs can be placed in areas to prohibit the use of Jake Brakes. This is because of their excessive noise which can be disruptive to the surrounding area.
- Ensure your engine has warmed up before using your Jake Brake.
- Check that your engine isn’t low on oil before use.
- Operate the Jake Brake in the shifting range of about 1100-1400 RPMs – this will help protect the motor.
If you’re interested in learning more about Jake Brakes and how to use them, check out our CDL training school for instruction on this type of brake system and more.