Exhaust Brake
Important: The exhaust brake is a vehicle slowing device, not a vehicle stopping device. It is not a substitute for the vehicle service brakes. Use of the exhaust brake for vehicle downhill control and slowing down on level terrain will allow the service brakes to remain cool and ready for an emergency.
Warning: Do not use the exhaust brake if road surfaces are slippery. Using the exhaust brake on wet, icy, or snow-covered roads could result in loss of vehicle control, possibly causing personal injury or death, or property damage.
The exhaust brake is activated when the following conditions are satisfied.
- The ON/OFF switch is in the ON position.
- The accelerator pedal is not depressed.The Allison transmission provides for optimum retarding by downshifting when the exhaust brake is selected. When the switch is turned ON and the driver's foot is removed from the accelerator pedal, the transmission will immediately preselect a lower gear. The transmission then starts to downshift through gears to reach the preselected gear. Downshifting occurs at a higher speed than is usual when the exhaust brake is not turned on. This allows the exhaust to provide the maximum retarding power.