2003 GMC SIERRA Fluid

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 fan is spinning slower and 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 as the clutch more fully 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 partially
disengages.
Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steeringfluid
unless you suspect there is a leak in the system or
you hear an unusual noise. Afluid loss in this system
could indicate a problem. Have the system inspected
and repaired. SeeEngine Compartment Overview
on page 5-12for reservoir location.
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How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at thefluid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enoughfluid to bring the level up to
the mark.
What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-15.
Always use the properfluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washerfluid, be sure to read
the manufacturer’s instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use afluid that has
sufficient protection against freezing. SeeEngine
Compartment Overview on page 5-12for reservoir
location.
Adding Washer Fluid
Open the cap with the
washer symbol on it. Add
washerfluid until the
tank is full.
Notice:
•When using concentrated washerfluid, follow the
manufacturer’s instructions for adding water.
•Don’t mix water with ready-to-use washerfluid.
Water can cause the solution to freeze and
damage your washerfluid tank and other parts of
the washer system. Also, water doesn’t clean as
well as washerfluid.
•Fill your washerfluid tank only three-quarters full
when it’s very cold. This allows for expansion if
freezing occurs, which could damage the tank if
it is completely full.
•Don’t use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
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Brakes
Brake Fluid
Your brake master cylinder reservoir isfilled with DOT-3
brakefluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brakefluid level in
the reservoir might go down. Thefirst is that the
brakefluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
thefluid level goes back up. The other reason is
thatfluid is leaking out of the brake system. If it is, you
should have your brake systemfixed, since a leak
means that sooner or later your brakes won’t work well,
or won’t work at all.
So, it isn’t a good idea to“top off”your brakefluid.
Adding brakefluid won’t correct a leak. If you addfluid
when your linings are worn, then you’ll have too
muchfluid when you get new brake linings. You should
add (or remove) brakefluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brakefluid, it can spill on
the engine. Thefluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See“Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brakefluid. SeePart C: Periodic
Maintenance Inspections on page 6-14.
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Checking Brake Fluid
You can check the brakefluid without taking off the cap.
Just look at the brakefluid reservoir. Thefluid level
should be above MIN. If it isn’t have your brake system
checked to see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
What to Add
When you do need brakefluid, use only DOT-3 brake
fluid. Use new brakefluid from a sealed container
only. SeePart D: Recommended Fluids and Lubricants
on page 6-15.
Always clean the brakefluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind offluid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper brake
fluid.
Notice:
•Using the wrongfluid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they’ll have to be replaced.
Don’t let someone put in the wrong kind offluid.
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All-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart C: Periodic
Maintenance Inspections on page 6-14.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of thefiller plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of thefiller plug hole.
Use care not to overtighten the plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-15.
(A) Fill Plug (B) Drain Plug
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Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart A: Scheduled
Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.The proper level is from 5/8 inch to 1 5/8 inch (15 mm to
40 mm) below the bottom of thefiller plug hole. Add
only enoughfluid to reach the proper level. The proper
level for vehicles with QUADRASTEER™(4 Wheel
Steer) is from 0 to 1/4 inch (0 to 6 mm) below thefiller
plug hole. Add only enoughfluid to reach the proper
level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-15.
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Front Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See Part A:Part A:
Scheduled Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.If the level is below the bottom of thefiller plug hole,
you may need to add some lubricant.
When the differential is cold, add enough lubricant to
raise the level to 0 to 3/8 inch (9.5 mm) below thefiller
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of thefiller plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Part D:Part D:
Recommended Fluids and Lubricants on page 6-15.
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Weatherstrips
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth at least every six
months. During very cold, damp weather more frequent
application may be required. SeePart D: Recommended
Fluids and Lubricants on page 6-15.
Cleaning the Outside of Your
Vehicle
The paintfinish on your vehicle provides beauty, depth
of color, gloss retention and durability.
Washing Your Vehicle
The best way to preserve your vehicle’sfinish is to keep
it clean by washing it often with lukewarm or cold
water.
Don’t wash your vehicle in the direct rays of the sun.
Use a car washing soap. Don’t use strong soaps
or chemical detergents. Be sure to rinse the vehicle
well, removing all soap residue completely. You can get
GM-approved cleaning products from your dealer.
SeeGM Vehicle Care/Appearance Materials on
page 5-88.Don’t use cleaning agents that are petroleum
based, or that contain acid or abrasives.All cleaning agents should beflushed promptly and not
allowed to dry on the surface, or they could stain.
Dry thefinish with a soft, clean chamois or an all-cotton
towel to avoid surface scratches and water spotting.
High pressure car washes may cause water to
enter your vehicle.
If your vehicle is equipped with QUADRASTEER™see
QUADRASTEER™on page 4-12.
Cleaning Exterior Lamps/Lenses
Use only lukewarm or cold water, a soft cloth and a car
washing soap to clean exterior lamps and lenses.
Follow instructions under“Washing Your Vehicle.”
Finish Care
Occasional waxing or mild polishing of your vehicle by
hand may be necessary to remove residue from the
paintfinish. You can get GM-approved cleaning products
from your dealer. SeeGM Vehicle Care/Appearance
Materials on page 5-88.
If your vehicle has a“basecoat/clearcoat”paintfinish.
The clearcoat gives more depth and gloss to the colored
basecoat. Always use waxes and polishes that are
non-abrasive and made for a basecoat/clearcoat paint
finish.
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