To Use the Engine Coolant Heater
1. Turn off the engine.
2. Find the plug-in receptacle located under the
driver’s door.
3. Plug a heavy-duty, three-prong extension cord
(rated for at least 15 amps) into the vehicle’s
plug-in receptacle first. Then plug the extension
cord into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. Use a
heavy-duty three-prong extension cord rated
for at least 15 amps.4. Before starting the engine, be sure to unplug
the cord.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature.
Usually, the coolant heater should be plugged in a
minimum of four hours prior to starting your vehicle.
From 32°F to−10° F (0°C to−23°C), keep the coolant
heater plugged in at least two hours. Below−10°F
(−23°C), keep the coolant heater plugged in for
a minimum of eight hours or overnight. It will not harm
either the coolant heater or the vehicle to leave the
coolant heater plugged in longer than the times stated.
Be sure to remove and store the cord before starting
the engine. SeeWhat Fuel to Use on page 5-8for
information on what fuel to use in cold weather.
2-24
Diesel Engine Exhaust Brake
The exhaust brake is available on vehicles equipped
with a diesel engine. It is located in the exhaust system.
The exhaust brake is used to help slow the vehicle
and may assist the vehicle’s foundation brakes. The use
of the exhaust brake will assist the braking of the
vehicle and prolong the life of the foundation brake
lining material.
The exhaust brake switch
is located in the instrument
panel switchbank.
Push the bottom of the switch to turn the exhaust brake
on. When you push the top of the switch, the exhaust
brake will turn off.There is an indicator light on the instrument panel
similar to the symbol on the switch, that will come on
when the exhaust brake is active. SeeExhaust
Brake Indicator Light on page 3-40for more information.
When using the exhaust brake, the proper gear range
selection is important. The exhaust brake will be
most effective if the gear range selected is the lowest
possible range that does not allow the engine rpm to go
more than 200 rpm above rated (full load) rpm. If you
have a Caterpillar
®diesel engine, do not exceed
2900 rpm. If you have a DURAMAX™ (LG4) diesel
engine, do not exceed 2400 rpm. If you have a
DURAMAX™ (LB7) diesel engine, do not exceed
3600 rpm.
If you have an automatic transmission and press this
button, the transmission will downshift to a factory
default setting of fourth gear. To change the default
setting, or for more information on factory default
settings, contact your dealer for assistance.
The accelerator and clutch pedals must be released in
order for the exhaust brake to engage. The exhaust
brake will not function when the cruise control feature is
active, and will automatically shut off when the
anti-lock brake system is active.
2-25
Two-Speed Rear Axle Electric
Shift Control
If your vehicle is equipped with this feature, you’ll find a
label on the headliner above the windshield or in
another place near the driver that shows how to use it.
Be sure to follow the directions carefully.
Use the following directions based on the type of shift
control you have.
Manual Transmission
The rear axle shift control
switch for a manual
transmission is located on
the shift lever.
When the switch is up, the rear axle is in the high
range. Push the switch down to change to low range.The two-speed axle should be in low when you park the
vehicle. You’ll need to engage the transmission, even
move the vehicle a little, to be sure the axle is in the low
range. Then apply the parking brake, shift into
NEUTRAL and shut off the engine.
Also, always start the vehicle in motion with the
two-speed axle in the low range. To shift up from low to
high, do the following:
1. Move the switch up for the high range,
2. disengage the clutch, and
3. after a brief pause, engage the clutch and then
press down on the accelerator.
To shift down from high to low, do the following:
1. Move the switch down to low,
2. release the accelerator and then quickly apply
it again.
2-26
Air Shift Control (Automatic
Transmission)
The rear axle shift control
switch for an automatic
transmission is located in
the instrument panel
switchbank.
Press the bottom of the switch to get to the low range.
The switch indicator light will come on when the
vehicle is in low range. Press the top of the switch to
return to the high range.
The two-speed axle should be in low range when you
park the vehicle. You’ll need to engage the transmission,
even moving the vehicle a little, to be sure the axle is
in low range. Then shift into PARK (P), apply the parking
brake and shut off the engine.To shift up from low to high, press the top of the rear
axle shift control switch and press down on the
accelerator. When you shift the axle from high to low,
press the bottom of the switch, release the accelerator
and then quickly press it down again.
To operate off-road or under a heavy load, shift into low
range when the vehicle is standing still and then
operate the transmission normally.
On the highway, with the axle in low range and the
transmission in top gear, you may shift the axle to high
range by raising the switch and releasing the
accelerator momentarily. Reapply the accelerator after
you shift.
Under light load conditions, first shift the axle into the
high range with the vehicle at a standstill and then
operate the transmission normally.
Air Suspension
Your vehicle may be equipped with the Hendrickson
HAS Series single-axle air suspension which is designed
for single-axle on-highway use. The feature is available
in 19,000 lb. (8 618.3 kg), 21,000 lb. (9 525.4 kg)
and 23,000 lb. (10 432.6 kg) capacities for operations
which require extra cubic capacity and a reduced
deck height.
2-27