Engines The exhaust brake is a butterfly type valve mounted in the exhaust pipe. When the driver’s foot is not on the accelerator pedal and the exhaust brake switch is in the on position, an air cylinder shuts the butterfly valve which restricts the flow of exhaust gases and retards the engine. This retarding action is carried through the engine and drivetrain, slowing the vehicle and reducing the need for frequent service brake applications. CAUTION Do not allow the engine to exceed its governed speed or serious engine damage could result. Apply the service brakes to reduce the engine rpm or make a slower descent by using a lower gear.
Exhaust brakes are not intended for use as the primary braking system during vehicle operation. WARNING Starting the Engine Do not use the exhaust brake when driving on slip- pery or low traction road surfaces. Failure to follow this precaution could result in a loss of vehicle con- trol and possible personal injury or property dam- age. Before starting the engine, make sure that the exhaust brake switch is in the off position. Do not turn the ex- haust brake on until the engine has reached normal op- erating temperatures. Exhaust Brake Operating Characteristics Driving Downhill While approaching a steep grade, make sure that the exhaust brake switch is in the on position.
The exhaust brake comes on as soon as you remove your foot from the accelerator pedal. While going down the grade, use a low enough gear to safely descend with a minimum application of the service brakes. As a general guide- line, use the same gear as you would to ascend the hill. When you remove your feet from both the accelerator and clutch pedals and the exhaust brake switch is in the on position, the exhaust brake is applied. The fol- lowing conditions should exist if the brake is operating properly: A slight change in the sound of the engine may be noticed when the exhaust brake is applied. Exhaust smoke should appear normal.
Engine temperature should remain in the normal operating range. 4.30