At what speed does the Type 3 jake brake disengage?

The Type 3 jake brake is designed to enhance engine braking capabilities, thereby allowing for better control of a vehicle on downhill slopes or during emergency stops. It typically disengages at a speed range of 3 to 5 MPH. This speed range is established to ensure that the engine braking function is effective during higher speeds, while providing a smooth transition to full braking capability as the vehicle slows down. Disengaging at this speed helps prevent unnecessary wear on the braking system and promotes better vehicle handling as it approaches a complete stop.

The other options present either lower or higher disengagement speeds, which do not align with the operational parameters of a Type 3 jake brake, thus reinforcing why the range of 3 to 5 MPH is the correct answer.