Have you ever seen a sign in your travels that says “No Engine Brakes” or “No Jake Brakes”? For anyone who doesn’t drive a commercial vehicle, these signs can be confusing. What are Jake brakes and why are they so disliked?
What Are Jake Brakes?
“Jake brakes” or “Jacob” brakes are colloquial names for a compression release brake. When a diesel engine slows down using its jake brakes, it opens the exhaust valves on top of the compression stroke. This would be similar to taking your foot off the gas so that gravity and other forces can slow your car down. In commercial trucks, when the exhaust valves are opened because of the compression release brake, the truck makes a noise that can only be described as a mile-long rumble strip, but deeper and more impressive.
The Ban Against Jake Brakes
Unfortunately, there are some communities that don’t appreciate the sound of Jake brakes as trucks pull into town. Few people know that Jake brakes are a very effective way to slow down the truck. The compression release brake will not only help drivers maintain control over their truck but will also increase the life of friction brakes. The trucking industry recognizes that these brakes are very helpful to the life of their rig.
The main areas where Jake brakes are prohibited are places where residential neighborhoods are near the interstate or toll roads. Everyone’s problem with Jake brakes is not that they are dangerous, but that they are loud. The sound is not irritating to some people, but many neighborhoods want to maintain peace in the early morning or late at night. Some towns will even fine truckers if they use their Jake brakes within a certain limit outside of town.
While we in the trucking industry know and respect the value of compression release brakes, the noises they make mean that they are misunderstood. It is important to teach people more about the trucking industry so that they understand why Jake brakes are used, and that that they are not just a noise that can disturb them at night.