
What is a Compression Release Engine Brake?
The Jacobs Engine Brake® is an engine retarder that uses the engine to aid in slowing and controlling the vehicle. When activated, the engine brake alters the operation of the engine’s exhaust valves so that the engine works as a power-absorbing air compressor. This provides a retarding, or slowing, action to the vehicle’s drive wheels, enabling you to have improved vehicle control without using the service brakes. This conservation results in reduced service brake maintenance, shorter trip times, and lower total cost of ownership.

Performance benefits of Jacobs’ Compression Release Brake
- Provides 85% of the vehicle’s braking needs
- Increases productivity by maintaining higher average downhill speed
- Reduces slowing time/distances of a heavily loaded vehicle from 90 to 70 kph in 30% less time and distance than with wheel brakes alone
- Lowers total cost of ownership
- Significantly reduces brake wear
- Eliminates “brake fade” due to high temperatures on the friction brakes; keeping them cool for maximum effectiveness when needed.
- Flexible solution available for your application

How Jacobs’ Compression Release Engine Brake works
When activated, when the engine is not fueling, the Jacobs’ Compression Release Brake opens the exhaust valves near the top of the compression stroke, releasing the highly compressed air through the exhaust system. The vehicle energy is used to push the engine to compress the air, but little energy is returned to the piston, and as the cycle repeats, the energy of the truck’s forward motion is dissipated, causing the truck to slow down.
Flexible Solutions
Dedicated Cam Rocker Brake
The benchmark for all heavy duty engine brake systems.
Lost Motion Bridge Brake
Engine brake function is integrated into the exhaust bridge.
Lost Motion Integrated Rocker Brake
Engine brake and exhaust function integrated into one rocker arm.
Bolt-on Slab Brake
Traditional solution with minimal or no impact to the standard valvetrain.
High Power Density
A combination of engine braking and cylinder deactivation to achieve higher retarding power.

Engine-specific solutions for leading OEMs



















