just a DA question regarding dp engine brakes

There is a second housing like a torque converter infront of the transmission. It has veins in there that the joystick operates from a slight turning to full on. This allows the full power of the drivetrain to slow you down. It is also hooked into you brake pedal too and just the retarder in full mire us like stepping on you brakes. I stop much faster and a retarder is more nuanced then a jake or exhaust brake with six positions. It is about a 20 k option from Allyson and is found standard on Foretravels featherlite and Liberty coaches. It is also on trash trucks since they stop and go all the time. In traffic I leave mine set at three and when I lift my foot I stop.

Peralko - in 500 words or less, can you explain how the transmission retarder actually works?

Bill

Peralko wrote:
The reason a gas engine brakes with the throttle closed is that it is pulling a vacuum with the throttle closed. A diesel engine always has a wide-open throttle, so no vacuum and no resistance. Modern DPs typically have one of three different engine braking systems. The first is an exhaust brake, which closes off the exhaust to create back pressure. It is the least effective. The Jake brake opens the exhaust valve for each cylinder at the top of the compression stroke, so the energy used to compress the air in the cylinder is not released on the downstroke-and the piston pulls a vacuum going back down. Jake brakes typically have two or three stages, depending on how many cylinders the Jake activates. The transmission retarder uses the transmission as a braking medium. The retarder is continually variable, and is as effective as a Jake. With any of the systems, the transmission is programmed to progressively go to lower gears when the engine brake is activated.

Excellent response.....exact and to the point......good job....Dennis

The reason a gas engine brakes with the throttle closed is that it is pulling a vacuum with the throttle closed. A diesel engine always has a wide-open throttle, so no vacuum and no resistance. Modern DPs typically have one of three different engine braking systems. The first is an exhaust brake, which closes off the exhaust to create back pressure. It is the least effective. The Jake brake opens the exhaust valve for each cylinder at the top of the compression stroke, so the energy used to compress the air in the cylinder is not released on the downstroke-and the piston pulls a vacuum going back down. Jake brakes typically have two or three stages, depending on how many cylinders the Jake activates. The transmission retarder uses the transmission as a braking medium. The retarder is continually variable, and is as effective as a Jake. With any of the systems, the transmission is programmed to progressively go to lower gears when the engine brake is activated.