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If No Steam Is Coming From
Your Engine
An overheat warning, along with a low coolant light,
can indicate a serious problem. SeeLow Coolant
Warning Light on page 173for more information.
If you get an engine overheat warning with no low
coolant light, but see or hear no steam, the
problem may not be too serious. Sometimes the
engine can get a little too hot when you:
•Climb a long hill on a hot day.
•Stop after high-speed driving.
•Idle for long periods in traffic.
If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL while stopped. If it is safe to do so,
pull off the road, shift to PARK (P) or
NEUTRAL and let the engine idle.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. If climbing a hill, downshift to raise engine and
fan speeds.If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.
If the warning continues and you have not
stopped, pull over, stop, and park your vehicle
right away.
If there is still no sign of steam, you can push
down the accelerator until the engine speed is
about twice as fast as normal idle speed for at least
three minutes while you are parked. If you still have
the warning, turn off the engine and get everyone
out of the vehicle until it cools down.
You may decide not to lift the hood but to get
service help right away.
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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 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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Power Steering Fluid
SeeScheduled Maintenance on page 363to
determine when to check your power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the
engine is warm. If the engine is not warm, you
probably will not get an accurate reading.
If the fluid level is between the MIN (Minimum) and
MAX (Maximum) marks, you have enough. If you
need fluid, add only enough of the proper fluid to
bring it in between the MIN and MAX marks.
If your power steering fluid level is low, this can
cause the brake or service brakes soon warning
lights to come on. In addition, the steering
effort and emergency brake distance could
increase.If either light remains on after you have added
power steering fluid to the proper level, then shut
off the engine for 10 seconds. This should
reset the brake warning lights. If one or both lights
stay on, see “Hydraulic Brake System Warning
Lights” underBrake System Warning Light
on page 169for more information.
What to Use
To determine what kind of fluid to use, see
Part C: Recommended Fluids and Lubricants on
page 397.
Notice:When adding power steering uid or
making a complete uid change, always
use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses
and seals.
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Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with the brakes.
Brake linings should always be replaced as
complete axle sets.
Four-Wheel and Six-Wheel Drum
Brakes (Air Only)
The brake drums should be removed and
inspected each time the tires are removed for
rotation or changing. When you have the
front brakes replaced, have the rear brakes
inspected, too.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return
to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
is needed.
Brake Adjustment
Every time you make a brake stop, the brakes
adjust for wear.
Brake Adjustment on Air Braked
Vehicles
Your vehicle has automatic slack adjusters.
Every time you make a brake stop, the brakes
automatically adjust for wear. Slack adjusters
should never be manually adjusted to correct
excessive brake chamber pushrod stroke.
Excessive brake chamber pushrod stroke means
that the brake system needs to be serviced by
a qualified service technician.
Notice:Do not manually adjust automatic slack
adjusters. Manual adjustment of the automatic
slack adjusters can result in a degradation of
the slack adjuster performance over time.
If the brake chamber pushrod stroke is out of
adjustment, the brake system needs to be
serviced by a quali ed service technician.
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Electric Air Compressor
Your vehicle may have an electric air compressor.
This compressor is used to run options that
require pressurized air, such as an air horn, air
seat, 7.8L engine exhaust restrictor, or 7.8L engine
exhaust brake.
The air compressor is used when vehicles do not
have an air brake system.
The air supply for
this system must be
maintained by releasing
the drain valve to eject
any moisture that
may have built up in
the system.
It is recommended that this system be drained on
a weekly basis.
Clutch Pedal Free Travel
If you have a V8 engine and a manual
transmission, the clutch will need adjustment
when pedal free travel gets down to about 1/4 inch
(6 mm), as measured at the clutch pedal pad.
You should have 1 1/2 to 2 inches (38 to 51 mm)
of clutch pedal free travel.
If the clutch ever needs service, be sure to use
only GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the
required chassis lubrication intervals and identifies
proper lubricants to use. Be sure to see the
Maintenance Schedule before performing any
chassis lubrication service. To determine location of
chassis lubrication items, use the following charts.
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7. Do not let the other end touch metal. Connect
it to the positive (+) terminal of the good
battery. Use a remote positive (+) terminal if
the vehicle has one.
8. Now connect the black negative (−) cable to
the negative (−) terminal of the good battery.
Use a remote negative (−) terminal if the
vehicle has one.
Do not let the other end touch anything until
the next step. The other end of the negative (−)
cable does not go to the dead battery. It
goes to a heavy, unpainted metal engine part
or to the remote negative (−) terminal on
the vehicle with the dead battery.9. Connect the other end of the negative (−) cable
at least 18 inches (45 cm) away from the dead
battery, but not near engine parts that move.
The electrical connection is just as good there,
and the chance of sparks getting back to the
battery is much less.
10. Now start the vehicle with the good battery
and run the engine for a while. Use the high
idle option if your vehicle is equipped with it.
11. Try to start the vehicle that had the dead
battery. If it will not start after a few tries, it
probably needs service.
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Page 317 of 430

Other Service Items
Fuel Filter
Fuel Filter/Pressure Regulator
(Gasoline Engines)
The steel fuel filter/pressure regulator is located
near the engine compartment on the driver’s
side frame rail. If your vehicle has a rear steel fuel
tank, the fuel filter/pressure regulator is located
near the rear fuel tank, on the driver’s side frame
rail. SeeScheduled Maintenance on page 363
for recommended service intervals.
If your vehicle is equipped with the optional Davco
spin-on type filter, it is located on the driver’s
side frame rail.
Fuel Filter (Diesel Engines)
If you have a diesel engine, your fuel filter is
located in the engine compartment on the driver’s
side of the vehicle, or along the driver’s side
frame rail. See “Fuel Filter Replacement” earlier in
this section for further information.
Also seeScheduled Maintenance on page 363for
recommended service intervals.
Primary Fuel Filter and Water
Separator
If you have a diesel
engine, you may have
this spin-on filter. It
is located on the driver’s
side frame rail.
It has a clear plastic drain bowl at the bottom.
Check the drain bowl occasionally for any water or
particles.
To drain the bowl, do the following:
1. Shut off the engine.
2. Partially open the drain valve at the bottom of
the filter.
SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 268orEngine Oil (Gasoline Engine) on
page 268orEngine Oil (DURAMAX
®/Isuzu Diesel
Engine) on page 272for proper disposal
procedures.
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Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your GM Warranty booklet for
details. For additional information refer to the tire
manufacturer’s booklet included with your vehicle.
{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much friction. You could have an
air-out and a serious accident. See
Loading Your Vehicle on page 238.
CAUTION: (Continued)
CAUTION: (Continued)
Underin ated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your vehicle’s tires are cold. See
Inflation - Tire Pressure on page 322.
Overin ated tires are more likely to be
cut, punctured, or broken by a sudden
impact — such as when you hit a
pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents. If
the tire’s tread is badly worn, or if
your vehicle’s tires have been
damaged, replace them.
321