Not all of the signs on the highway pertain to you and your vehicle. You’ve never seen an SUV or minivan pulled into a weigh station; these areas are only for semi-trucks. Most of the signs that say “No Engine Brakes” only pertain to vehicles with a Jake brake. These vehicles are some large trucks and semis.
What is a Jake brake?
A Jake brake is a special engine braking system that uses the exhaust valves to slow it down. When truckers activate this system, the exhaust valves are opened at the top of the compression stroke, allowing this engine system to slow the truck. This is similar to taking your foot off the gas but a little more forceful.
Does this braking system benefit semi-trucks?
Yes, the engine and exhaust system are used instead of using the traditional brakes on the wheels to slow the vehicle. This allows the regular brakes to last longer, and the semi can slow to a stop more easily.
Why do some areas ban this braking system in semi-trucks?
According to the Apex CDL Institute, some communities don’t appreciate the sound that comes from the Jake brakes. These brakes make an incredibly loud sound that can come from these brakes. When engaged, some feel this brake sounds like a gunshot and continues to be loud while the system is engaged.
Communities that have banned these brakes often post signs that read “No Engine Brakes.” Some areas have signs with time to ensure truckers don’t engage the Jake brakes early in the morning or late at night. Truckers who ignore the signs will fine truckers who use them in areas where they are prohibited.
Does this braking system hurt the engine or use more fuel?
No, the Jake Brake doesn’t use more fuel or hurt the engine. This brake could only hurt the engine when the driver pushes the engine’s RPM level over its maximum just before engaging these brakes. Engine braking also shuts off fuel consumption, which is a benefit compared to normal braking or shifting the truck into neutral.
What’s the origin of the Jake brake name?
As expected, the name comes from the product that is named the Jacobs Engine Brake. The company that first made these brakes, Jacobs Vehicle Systems, calls the system a diesel engine retarder that uses the engine to slow the vehicle that uses the exhaust valve operation to cut down on the engine power and slow the semi-truck.
Does my car have this braking system?
You won’t have a Jake brake unless you drive a large truck. Typically, these brakes are only used in semi-trucks, but some heavy-duty trucks have them. In fact, some modern versions of the Ford F-250 Super Duty have engine brakes. Although this Ford has this braking system, these engine brakes are becoming much less common in regular trucks.
If you’ve ever heard a large semi-truck slow down and hear a deafening noise from the engine, that’s the Jake brake engaging. While useful, this system is extremely loud and a big part of most truckers’ world.
Next, check out some reasons a semi-truck might be tailgating you, or learn more about the Jake brake in the video below: