During operation of the vehicle, the operator should limit the engine speed to 1900
rpm or less. No extra engine power is achieved at engine speeds above 1900 rpm.
Shifting gears without pressing the clutch, or using the engine brakes to reduce
engine speed, may result in serious powertrain damage due to higher engine speeds.
Never exceed 2000 rpm as higher engine speeds may result in extensive engine
damage.
Any engine overspeed (engine speed exceeds 2500 rpm) while the vehicle is
moving (vehicle speed over 0 MPH) is considered to be an operator-induced engine
overspeed. Any mechanical engine failure within 3218 km (2000 mi) of an
operator-induced engine overspeed event will not be eligible for Detroit warranty
coverage.
Operate the engine brakes when descending a long, steep grade as follows:
1. Before beginning the descent, determine if the brake system is operating
properly by briefly depressing the accelerator pedal. The operator should be
able to feel the system activate.
2. Ensure the engine brake is in the appropriate power position (LOW/MED/
HIGH).
CAUTION: BRAKE FADE
To avoid injury, do not over apply the vehicle service brakes when
descending a long, steep grade. Excessive use of the vehicle
brakes will cause them to heat up, reducing their stopping ability.
This condition, referred to as “brake fade”, may result in loss of
braking, which could lead to personal injury or vehicle/property
damage or both.
3. Do not exceed the safe control speed of the vehicle. Example: An operator
could descend a 6% grade, under control only at 16 kph (10 mph) without
an engine brake, but at 40 kph (25 mph) with an engine brake. Do not
descend that same hill at 80 kph (50 mph) and still expect to remain under
control. Operators should get to know how much slowing power the engine
brakes can provide. Operators should get to know the engine brake system
before climbing hills and should not exceed a safe control speed.
WARNING: PERSONAL INJURY
Failure to keep the vehicle within safe control speed limits while
descending a grade may result in loss of vehicle control, which
could cause personal injury.
4. Check the engine brake status often for proper position (LOW/MED/HIGH)
since road conditions can change quickly. Never skip a step when operating
the engine brake system. Always go from OFF to LOW and then to a higher
position.
How to Procedures
82
All information subject to change without notice.
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DDC-SVC-MAN-0217
