Controls and Operating
3-29
Engine Exhaust Brake
Press the bottom of the engine exhaust brake request switch to select the
engine exhaust brake. The engine exhaust brake symbol will illuminate on
the display screen when the engine exhaust brake is engaged.
NOTICE: For the Engine Exhaust Brake to activate -
a) the ECU must be live. Engine speed must be greater than 1000 rpm
b) the throttle pedal should be deactivated
c) the throttle pedal position must be less than 5%
The engine exhaust brake is applied automatically when throttle pedal is
released and engine speed is greater than 1000 rpm.
The engine exhaust brake also operates when ever the service brake is
applied.
Operation
Before the machine starts down the gradient fully laden, it is
recommended that the descent gear be preselected manually (Refer to
Section 3. The manually pre-selected gear should be high enough to keep
the engine operating at governed speed. Generally the gear used to
ascend a grade, fully laden, is also correct for its descent. Please refer to
the gradeability decal for recommended gear selection per grade
specification. The engine exhaust brake can now be selected and the
acceleration released (off gas). If the rate of descent is too slow, the trans-
mission should be upshifted to the next highest gear. If the rate of descent
is too fast, the service brakes should be applied and the transmission
shifted into a lower gear which will allow a safe descent and efficient
engine exhaust braking. If further braking is required, apply the service
brakes.
WARNING
If descending a steep gradient in a laden truck in automatic gear
shift mode, the transmission E.C.U. may automatically upshift to
prevent a machine (engine) over-speed condition. Also, if the
accelerator is re-applied when engine exhaust brake is actuated
and the truck is in automatic gear shift mode, a rapid acceleration
(increase in ground speed) and gear upshift could occur.
To Next Page
Loading...