Practice question

What is the function of the engine compression release brake commonly known as the 'Jacobs Brake' or 'Jake Brake'?

It injects extra diesel fuel to increase acceleration
It opens exhaust valves near top dead center of the compression stroke, releasing compressed air into the exhaust so the energy stored in compressed air is not returned to the piston on the power stroke, turning the engine into an air compressor that absorbs power
It locks the front steering wheels mechanically
It disconnects the transmission from the driveshaft

Answer: B — It opens exhaust valves near top dead center of the compression stroke, releasing compressed air into the exhaust so the energy stored in compressed air is not returned to the piston on the power stroke, turning the engine into an air compressor that absorbs power

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