Page 103 of 430

Stopping the Diesel Engine
1. Set the parking brake and shift to
NEUTRAL (N) or PARK (P).
2. Turn the ignition key to OFF.
If your vehicle has a two-speed axle, see
Two-Speed Rear Axle Electric Shift Control on
page 113.
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 262.
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
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.
103
Page 284 of 430

Engine Coolant (Gas and
DURAMAX
®/Isuzu 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 288.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 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. See
Part C: Recommended Fluids and Lubricants
on page 397for more information.
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Page 286 of 430
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.
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Page 290 of 430
Cooling System (Gas and
DURAMAX
®/Isuzu Engines)
When you decide it is safe to lift the hood, here is
what you will see:
A. Engine Fan
B. Coolant Surge TankIf 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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Page 291 of 430

{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 your
engine without coolant is not covered by your
warranty.Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant could 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.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at the FULL
COLD mark or higher, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at
the coolant surge tank, but be sure the cooling
system, including the coolant surge tank pressure
cap, is cool before you do it. SeeEngine
Coolant (Gas and DURAMAX
®/Isuzu Engines) on
page 284orEngine Coolant (Caterpillar®Diesel
Engines) on page 287for more information.
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If no coolant is visible in the surge tank, add
coolant as follows:
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
{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: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.
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{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.
293