What Does A Jake Brake Do?
A jake brake changes the timing of the engine and turns it into a power absorber by opening the exhaust valve at the end of the compression stroke. You start to use the motor to retard the speed of the truck.
When to Use Your Jake Brake
- You can use it anytime it’s safe to do so. Using your jake to slow from highway speeds saves your service brakes. You can’t bring the truck to a complete stop with it but you can reduce your speed significantly before applying your service brakes. This will increase the life of your service brakes.
- Jakes are a must in the mountains. Long downhill grades can heat up your brakes to a point where they no longer slow the truck. A truck with no brakes is referred to as a runaway and it’s deadly.
- If your brakes get hot enough to reduce performance they can also start a tire fire. When you’re going to travel down a significant grade, slow down and gear down to where the jake will do most of the work and you will only need to apply short service brake applications.
- You don’t want to use your jake on slippery roads. If you do use your jake on a slippery roadway – use it at a lower setting. Jake’s have 3 settings and most of them now have an additional adaptive setting to use with cruise control. The adaptive setting allows you to set the jake to come on at a designated speed higher than your cruise control is set. This is useful for hilly areas.
- Jake brakes are loud. Most cities and municipalities have noise ordinances prohibiting the use of jake brakes. Follow the local noise ordinances as much as possible. Unless you’re confronted with a major grade coming into a mountain town you have no real need to disrupt the locals with a loud jake brake.
- While we haven’t done any polling, I’m confident in guessing about 10 out of 10 truck drivers don’t want their sleep disrupted in a truck stop by your jake brake. Ensure you turn it off before you enter a truck stop or rest area.
Your Jake brake is a useful tool to slow and maintain control of your truck and save wear on the equipment. It’s a safety feature that you should use.