PANEL GP-CAB 2810033 - Caterpillar

Descending a Grade
Before beginning a long, steep descent, determine if your Jake Brake is operating properly. This can be done by lifting your foot briefly off the accelerator pedal. The Jake Brake is working correctly if the vehicle begins to slow down.Note: The following road speeds and grades are given as examples only! Actual conditions and retarding performance will vary.
Illustration 9 g00731973An explanation of control speed is helpful in understanding the use of the Jake Brake while you are descending a grade. Control speed is the constant speed that occurs when the forces that are pushing the vehicle down a grade are equal to the forces that are holding the vehicle back without using the service brakes. In other words, vehicle speed will be maintained without using the service brakes.
Illustration 10 g00731981You may be able to safely descend a 6 percent grade at 10 mph without using the service brakes or the Jake Brake. This is dependent on the road conditions and the load that is being carried.
Illustration 11 g00731989It may be possible to maintain control of the vehicle while descending a 6 percent grade at 25 mph without using the service brakes with the Jake Brake set to the "HIGH" position on the progressive braking switch.Note: The Jake Brake can be kept on for as long as needed without any risk of engine overheating or damage.
Illustration 12 g00731993Under some circumstances, you may want to descend a grade at a faster rate than the control speed. This can be done by selecting a higher gear, or a lower position on the progressive braking switch. However, you may need to apply the service brakes intermittently. Applying the service brakes will help prevent engine overspeed. Applying the service brakes will also help keep the vehicle at a safe speed.
Frequent use of the service brakes will cause the service brakes to heat up, reducing the stopping ability of the vehicle. The result can be a dangerous condition called brake fade.
There may be circumstances when you might want to descend a grade at a rate that is slower than the control speed. This is done by selecting a lower gear. Do not select a gear that is low enough to result in an engine overspeed. You may need to apply the service brakes in order to obtain the desired lower speed.The Jake Brake can be misused. Look at the example of descending the 6 percent grade under control only at 10 mph without a compression brake, but at 25 mph with a compression brake. You could not expect to maintain control of the vehicle on the same grade at 50 mph. Become familiar with the amount of retarding power that can be provided by your Jake Brake. Never exceed a safe control speed.Slippery Pavement
The operation of any vehicle can be unpredictable in slippery conditions. Be careful when you are testing the Jake Brake on slippery roads.The Jake Brake will not affect the operation of the ABS. The ECM will deactivate the Jake Brake when the ABS