Page 288 of 424
Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Cooling Fan
If the coolant inside the coolant recovery tank is boiling,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.When the engine is cold, the coolant level should be at
least up to the ADD mark. If it isn’t, 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.
5-30
2003 - Sonoma OM
Page 290 of 424

How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the ADD mark, add a 50/50 mixture ofclean,
drinkable waterand DEX-COOL
®engine coolant at the
coolant recovery tank. SeeEngine Coolant on
page 5-25for more information.
{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 wouldn’t 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.
{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. Don’t spill coolant on a hot engine.
5-32
2003 - Sonoma OM
Page 298 of 424

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 6-33.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 of uid 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 uid.
Notice:
Using the wrong uid 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 of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged. Be
careful not to spill brake uid on your vehicle.
If you do, wash it off immediately. See
“Appearance Care”in the Index.
5-40
2003 - Sonoma OM
Page 331 of 424
4. Raise the vehicle by turning the jack handle
clockwise. Raise the vehicle far enough off the
ground so there is enough room for the spare tire to
fit underneath the wheel well.
5. Remove all the wheel nuts and take off theflat tire.
6. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
{CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
the places where the wheel attaches to the
vehicle. In an emergency, you can use a cloth
or a paper towel to do this; but be sure to use
a scraper or wire brush later, if you need to,
to get all the rust or dirt off.
{CAUTION:
Never use oil or grease on studs or nuts. If
you do, the nuts might come loose. Your wheel
could fall off, causing a serious accident.
7. Place the spare on the wheel mounting surface.
5-73
2003 - Sonoma OM
Page 338 of 424

Using Cleaner on Fabric
1. Vacuum and brush the area to remove any
loose dirt.
2. Always clean a whole trim panel or section.
Mask surrounding trim along stitch or welt lines.
3. Follow the directions on the container label.
4. Apply cleaner with a clean sponge. Don’t saturate
the material and don’t rub it roughly.
5. As soon as you’ve cleaned the section, use a
sponge to remove any excess cleaner.
6. Wipe cleaned area with a clean, water-dampened
towel or cloth.
7. Wipe with a clean cloth and let dry.
Special Fabric Cleaning Problems
Stains caused by such things as catsup, coffee (black),
egg, fruit, fruit juice, milk, soft drinks, vomit, urine
and blood can be removed as follows:
1. Carefully scrape off excess stain, then sponge the
soiled area with cool water.
2. If a stain remains, follow the cleaner instructions
described earlier.3. If an odor lingers after cleaning vomit or urine,
treat the area with a water/baking soda solution:
1 teaspoon (5 ml) of baking sold to 1 cup (250 ml)
of lukewarm water.
4. Let dry.
Stains caused by candy, ice cream, mayonnaise, chili
sauce and unknown stains can be removed as follows:
1. Carefully scrape off excess stain.
2. First, clean with cool water and allow to dry
completely.
3. If a stain remains, follow the cleaner instructions
described earlier.
Vinyl
Use warm water and a clean cloth.
•Rub with a clean, damp cloth to remove dirt.
You may have to do this more than once.
•Things like tar, asphalt and shoe polish will stain if
you don’t get them off quickly. Use a clean cloth
and vinyl/leather cleaner. See your dealer for
this product.
5-80
2003 - Sonoma OM
Page 339 of 424

Leather
Use a soft cloth with lukewarm water and a mild soap or
saddle soap and wipe dry with a soft cloth. Then, let
the leather dry naturally. Do not use heat to dry.
•For stubborn stains, use a leather cleaner. See your
dealer for this product.
•Neveruse oils, varnishes, solvent-based or abrasive
cleaners, furniture polish or shoe polish on leather.
•Soiled or stained leather should be cleaned
immediately. If dirt is allowed to work into thefinish,
it can harm the leather.
Top of the Instrument Panel
Use only mild soap and water to clean the top surfaces
of the instrument panel. Sprays containing silicones
or waxes may cause annoying reflections in the
windshield and even make it difficult to see through the
windshield under certain conditions.
Interior Plastic Components
Use only a mild soap and water solution on a soft cloth
or sponge. Commercial cleaners may affect the
surfacefinish.
Wood Panels
Use a clean cloth moistened in warm, soapy water
(use mild dish washing soap). Dry the wood immediately
with a clean cloth.
Glass Surfaces
Glass should be cleaned often. GM Glass Cleaner or a
liquid household glass cleaner will remove normal
tobacco smoke and dustfilms on interior glass. See
GM Vehicle Care/Appearance Materials on page 5-86.
Notice:Don’t use abrasive cleaners on glass,
because they may cause scratches. Avoid placing
decals on the inside rear window, since they
may have to be scraped off later. If abrasive cleaners
are used on the inside of the rear window, an
electric defogger element may be damaged. Any
temporary license should not be attached across
the defogger grid.
5-81
2003 - Sonoma OM
Page 341 of 424

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 5-86.
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
paintfinish.
Notice:Machine compounding or aggressive
polishing on a basecoat/clearcoat paint nish may
dull the nish or leave swirl marks.Foreign materials such as calcium chloride and other
salts, ice melting agents, road oil and tar, tree sap, bird
droppings, chemicals from industrial chimneys, etc.,
can damage your vehicle’sfinish if they remain
on painted surfaces. Wash the vehicle as soon as
possible. If necessary, use non-abrasive cleaners that
are marked safe for painted surfaces to remove
foreign matter.
Exterior painted surfaces are subject to aging, weather
and chemical fallout that can take their toll over a
period of years. You can help to keep the paintfinish
looking new by keeping your vehicle garaged or covered
whenever possible.
Protecting Exterior Bright Metal Parts
Bright metal parts should be cleaned regularly to keep
their luster. Washing with water is all that is usually
needed. However, you may use chrome polish on
chrome or stainless steel trim, if necessary.
Use special care with aluminum trim. To avoid damaging
protective trim, never use auto or chrome polish,
steam or caustic soap to clean aluminum. A coating of
wax, rubbed to high polish, is recommended for all
bright metal parts.
5-83
2003 - Sonoma OM
Page 344 of 424

GM Vehicle Care/Appearance
Materials
See your GM dealer for more information on purchasing
the following products.
GM Vehicle Care/Appearance Materials
Description Usage
Polishing Cloth
Wax-TreatedInterior and exterior
polishing cloth.
Tar and Road Oil
RemoverRemoves tar, road oil
and asphalt.
Chrome Cleaner and
PolishUse on chrome or
stainless steel.
White Sidewall Tire
CleanerRemoves soil and black
marks from whitewalls.
Vinyl CleanerCleans vinyl tops,
upholstery and
convertible tops.
Glass CleanerRemoves dirt, grime,
smoke andfingerprints.
GM Vehicle Care/Appearance Materials
(cont’d)
Description Usage
Chrome and Wire Wheel
CleanerRemoves dirt and grime
from chrome wheels and
wire wheel covers.
Finish EnhancerRemoves dust,
fingerprints, and surface
contaminants, Spray on
wipe off.
Swirl Remover PolishRemoves swirl marks,
fine scratches and other
light surface
contamination.
Cleaner WaxRemoves light scratches
and protectsfinish.
Foaming Tire Shine
Low GlossCleans, shines and
protects in one easy step,
no wiping necessary.
5-86
2003 - Sonoma OM