What Is Engine Braking or a Jake Brake?
A Jake Brake is the trademark name for a compression release engine braking system. Essentially, it’s an extra supplemental braking system to help stop the truck faster in addition to the traditional friction brakes on the wheels. With an air compression system, the engine will work to slow down the semi-truck.
18-wheeler truck engines are quite complicated. To put it simply, air enters the intake valve and is forced into the engine cylinders. That air is compressed, and the energy released is distributed by the pistons.