Peterbilt 579 - Descending a Grade; Engine Overspeed

DRIVING TIPS AND TECHNIQUES
4
Descending a Grade
WARNING!
Do not hold the brake pedal down too
long or too often while going down a
steep or long grade. This could cause
the brakes to overheat and reduce
their effectiveness. As a result, the
vehicle will not slow down at the usual
rate. To reduce the risk of an accident
which could cause death or personal
injury, before going down a steep or
long grade, reduce speed and shift the
transmission into a lower gear to help
control your vehicle speed. Failure to
follow procedures for proper downhill
operation could result in loss of vehi
-
cle control.
Engine Overspeed
CAUTION
To avoid engine damage, do not let the
engine rpm go beyond the maximum
governed rpm—valve damage could
result if overspeed conditions occur.
NOTE
Often these recommendations are
secondary to maintaining an adequate
and safe speed relative to the sur
-
rounding trafc and road conditions.
Operate the engine within the optimum
engine rpm range and do not allow
the rpm's to exceed the maximum
governed speed. See your Engine
Operation and Maintenance manual
for information regarding engine rpm.
When the engine is used as a brake
to control vehicle speed (e.g., while
driving down a grade), do not allow
the engine rpm to exceed maximum
governed speed.
Under normal
load and road conditions
operate the engine in the lower end of
the range.
4-54
Y53-6047–2C (04/13)