Which engine brake utilizes the compression stroke of the piston for retarding?

The internal compression brake utilizes the compression stroke of the piston to aid in retarding vehicle speed. This braking mechanism operates by modifying the operation of the engine's intake and exhaust valves, allowing the engine to effectively generate a braking force during the compression phase. When the brake is engaged, the engine compression creates a load that resists the motion of the piston, which in turn slows down the vehicle while maintaining engine efficiency.

In contrast, external compression brakes and hydraulic retarders do not specifically use the piston's compression stroke. External compression brakes often redirect the engine's exhaust gases to create resistance, while hydraulic retarders operate using fluid dynamics to provide braking force independent of the engine's compression cycle. Additionally, the Volvo EPG (Exhaust Pressure Governor) is a specific type of engine braking system that manages exhaust back pressure rather than directly using piston compression.

Understanding the function of internal compression brakes is crucial for truck and coach technicians, as these systems play an important role in managing vehicle stability and safety during operation.