Mack TerraPro LEU 2010, Operator'S Handbook Manual

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118 OPERATION
will again be activated. In order to disable the engine brake, simply return the
dash-mounted control switch to the OFF position.
DANGER
The engine brake should never be considered a substitute for the vehicle service
brakes. The service brakes should always be maintained in good working order,
and should always be viewed as the primary vehicle slowing system. Service
brakes are always used to bring the vehicle to a complete stop.
Cruise Control with the MACK PowerLeash™
Engine Brake
When the MACK PowerLeash™ Engine Brake is enabled at the same time
your V-MAC® cruise control is in use, the engine brake automatically activates
when necessary to slow the vehicle to the cruise set point speed. You can
select one of two possible options:
• The engine brake is activated 3 kph (2 mph) above the cruise set point.
• The engine brake is activated as soon as cruise control commands fueling to
zero (vehicle has just reached cruise set point and fuel has been turned off).
The first option is the more popular choice for highway use and is the default
mode. Consult your V-MAC® IV Operator’s Manual for more information
about this option. Your local MACK dealer can change the current selection.
The engine brake’s ability to control maximum vehicle speed is limited
to the selected retarding power of the engine brake. If the engine brake
dash-mounted control switch is set to the LOW position, only half of the
available braking power is used. If the dash-mounted control switch is set to
the HIGH position, the cruise control invokes full engine brake power.
Note: Deactivating the cruise control function does not disable the engine brake.
The MACK PowerLeash™ Engine Brake may be activated or deactivated by
other vehicle systems such as ABS and Headway control systems. Refer to
the literature concerning these systems for additional information.