Page 83 of 384

Stopping the Diesel Engine
1. Apply the parking brake. SeeParking Brake (With
Hydraulic Brakes) on page 2-38orParking Brake
(With Air Brakes) on page 2-41for parking
brake apply procedure.
2. Shift into NEUTRAL for a manual transmission or
PARK (P) for an automatic transmission.
3. Turn the ignition key to OFF.
If your vehicle has a two-speed axle, see
Two-Speed Rear Axle on page 2-27.
If you have a Caterpillar
®diesel engine, see your
Caterpillar®Diesel Engine Operation & Maintenance
Manual for additional information.
Diesel Engine Warm-Up
Several factors affect how quickly your diesel engine
warms up. These can include outside temperature,
engine load, idle time and your vehicle’s option content.
Your vehicle may be equipped with some features
that can help the engine reach operating temperature
sooner. Some of these features are discussed below.Also, remember that an automatic transmission adds
heat to the cooling system through the heat exchanger in
the radiator. Because of this, vehicles equipped with
automatic transmissions are often able to retain engine
coolant heat better than manual transmission vehicles.
See your Caterpillar
®Operation & Maintenance manual
for additional diesel engine warm-up information.
If Your Diesel Engine Will Not Start
If you have run out of fuel, seeRunning Out of Fuel on
page 5-17.
If you are not out of fuel, and your engine will not start,
do this:
Turn your ignition key to RUN. Immediately after the wait
to start light goes off, turn the ignition key to START.
If the light does not go off, wait a few seconds, then try
starting your engine again. And, see your dealer/retailer
as soon as you can for a starting system check.
If the light comes on and then goes off and you know
your batteries are charged, but your engine still will not
start, your vehicle needs service.
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How to Add Fluid
To add transmission fluid, do the following:
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of
the fill opening. Refer to the Maintenance
Schedule to determine the proper fluid to use.
SeePart C: Recommended Fluids and Lubricants
on page 6-31.
3. Reinstall the filler plug. Be sure the plug is fully
seated.
Engine Coolant (Caterpillar®Diesel
Engines)
If your vehicle has a Caterpillar®diesel engine, see the
Caterpillar®Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to
add, as well as when and how to service your cooling
system.
Engine Coolant (Gas and
DURAMAX
®/Isuzu 7.8L L6 Engines)
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 5-48.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
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What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
If you have to add coolant more than four times a year,
have your dealer/retailer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeePart C: Recommended
Fluids and Lubricants on page 6-31for more
information.
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Page 250 of 384
Checking Coolant
The coolant surge tank is located in the engine
compartment on the driver’s side of the vehicle.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be parked on a level surface. When
your engine is cold, the coolant level should be at the
FULL COLD mark or higher.
If the low coolant warning
light comes on in the
instrument panel cluster
and stays on, it means you
are low on engine
coolant.
SeeLow Coolant Warning Light on page 3-35for further
information.
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Page 254 of 384
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Engine Fan
B. Coolant Surge Tank
If your vehicle has a Caterpillar
®diesel engine, see the
Caterpillar®Diesel Engine Operation and Maintenance
Manual provided with your vehicle.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.The coolant level should
be at the FULL COLD
mark or higher. If it is not,
you may have a leak at
the pressure cap or in the
radiator hoses, heater
hoses, radiator, water
pump, or somewhere else
in the cooling system.
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{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it does not, your vehicle needs service. Turn off
the engine.Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
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Page 257 of 384
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
1. You can remove the
coolant surge tank
pressure cap when the
cooling system,
including the coolant
surge tank pressure
cap and upper radiator
hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait for that to
stop. A hiss means there is still some pressure left.2. Then keep turning the pressure cap slowly, and
remove it.
3. Fill the coolant surge tank with the proper mixture,
to the FULL COLD mark.
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4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches slightly above the FULL
COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This improves
fuel economy and reduces fan noise. Under heavy
vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise. This
is normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
Power Steering Fluid
SeeScheduled Maintenance on page 6-5to determine
when to check your power steering fluid.
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