What is a jake brake?

A Jake Brake, technically an engine brake, is a retardation system used primarily on large diesel engines, most often in heavy trucks. Here's a breakdown:

• Function: It slows down a vehicle by using the engine's compression stroke to create a braking effect. Unlike service brakes (wheel brakes), engine brakes don't rely on friction materials.

• How it Works: During the engine's normal four-stroke cycle (intake, compression, power, exhaust), the Jake Brake opens the exhaust valves near the top of the compression stroke. This releases the highly compressed air in the cylinder, preventing it from returning its energy to the piston on the power stroke. The engine, therefore, acts as an air compressor, absorbing energy and slowing the vehicle. Learn more about how%20it%20works.

• Benefits:

  • Reduced wear on service brakes: This leads to longer brake life and lower maintenance costs.
  • Improved vehicle control, especially on downhill grades.
  • Enhanced safety.
  • Preventing "brake fade": Overheating and loss of braking effectiveness due to prolonged use of service brakes.

• Operation: The driver typically activates the Jake Brake with a switch. Many systems offer multiple levels of braking power (e.g., low, medium, high), achieved by activating different numbers of cylinders. More on operation.

• Noise: Jake Brakes can be noisy, producing a distinct "staccato" sound. Due to noise pollution concerns, some municipalities restrict their use within city limits, especially at night. This is often indicated with signs that say "No Engine Braking".

• Alternative Names: While "Jake Brake" is the common term, it is technically a brand name. Other terms include "compression release engine brake" and simply "engine brake". Details on alternative%20names.

• Considerations: Jake Brakes are most effective at higher engine RPMs. Using them at too low of an RPM can cause the engine to lug and potentially stall. In icy or slippery conditions, the sudden deceleration caused by a Jake Brake can lead to a loss of traction and skidding. Information about considerations.