Navistar WorkStar Series, Operator'S Manual

Page: 151 / 258

Operation
3. If no leaks are found, resume driving at 15 mph slower
than when the indicator came on.
4. Resume safe speed if indicator stays off.
International® Ride Optimized Suspension (IROS) (Optional)
CAUTION
The vehicle must not be operated on the road
without air in the suspension bags.
This
will prevent suspension damage and ride
degradation. Failure to observe this may cause
property damage.
The International® Ride Optimized Suspension (IROS) is a
variable rate suspension system that automatically adjusts to
different loads to maintain constant frame height. The system
provides improved vehicle ride and increased driver comfort.
This feature also allows the rear of the vehicle to lower several
inches for cargo loading and unloading.
The system may be controlled by an optional two-position
SUSP/DUMP switch with an indicator in the DUMP position. This
switch controls solenoids, which directs air to the suspension
dump and height valve.
Air Suspension Dump (ASD) Switch (Optional)
NOTE: The suspension will dump when the ignition switch is
in either ACC or ON position, but will only fill when the ignition
switch is in the ON position.
NOTE: To lower the suspension (dump operation), the vehicle
speed must be less than 5 mph (8 km/h).
When the SUSP/DUMP switch is in the DUMP position
and the vehicle speed is below 5 mph (8 km/h), air
supplied to the air suspension is released, lowering the
frame for loading.
Placing the switch in the SUSP position causes air to fill
or remain in the air suspension for proper operating ride
height. The SUSP/DUMP switch will operate the IROS
system only if the ignition switch is in either ACC or ON positions
and the air tanks have sufficient pressure to fill the suspension.
When the ignition switch is turned OFF, power to the solenoid will
be removed. Therefore, the suspension will remain in the state
last set by the SUSP/DUMP switch.
NOTE: The SUSP/DUMP switch functions will be inhibited by
either a Traction Control or ABS event.
In either event for
either SUSP or DUMP operation, the ASD switch will have to
be manually recycled after the event has passed in order to
complete the operation.
The following is the operation of the optional air suspension
dump (SUSP/DUMP) switch in controlling the vehicle ride
height:
3879634R1
139