Grade Brake
Important: The grade brake is an optional auxiliary brake system that works through the transmission. It should not be confused with exhaust brake or engine brake. Furthermore, the grade brake should not be used in place of the service brakes to stop the vehicle.
Chassis equipped with a propane engine may have an optional grade brake. The grade brake is designed to downshift the transmission—when going downhill for example—without overspeeding the engine. Refer to the Allison Operator's Manual for proper operation of the grade brake. See Fig. for an example of the grade brake switch. An amber light activates at the top of the switch when the grade brake is activated.
