2003 GMC SONOMA coolant reservoir

A. Battery
B. Coolant Recovery Tank
C. Automatic Transmission Dipstick (If Equipped)
D. Engine Oil Fill Cap and Dipstick
E. Power Steering ReservoirF. Brake Master Cylinder
G. Engine Air Cleaner/Filter
H. Engine Compartment Fuse Block
I. Windshield Washer Fluid Reservoir
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2003 - Sonoma OM

When you open the hood on the 4300 V6 engine, you’ll see:
A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Automatic Transmission Dipstick (If Equipped)F. Power Steering Reservoir
G. Brake Master Cylinder Reservoir
H. Engine Air Cleaner/Filter
I. Engine Compartment Fuse Block
J. Windshield Washer Fluid Reservoir
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2003 - Sonoma OM

How to Check and Add Fluid
The properfluid should be added if the level does not
reach the bottom of the diaphragm when it’s in place
in the reservoir. See the instructions on the
reservoir cap.
Engine Coolant
The cooling system in your vehicle isfilled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occursfirst, 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 5-28.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:When adding coolant, it is important that
you use only DEX-COOL
®(silicate-free) coolant.
If coolant other than DEX-COOL®is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner -- at 30,000 miles
(50,000 km) or 24 months, whichever occursrst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new
vehicle warranty.
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2003 - Sonoma OM

What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-33.
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 5-10for reservoir location.
Adding Washer Fluid
Open the cap
with the washer
symbol on it.SeeEngine Compartment Overview on page 5-10for
more information on locationt. Add washerfluid until the
tank is full.
Notice:
When using concentrated washeruid, follow
the manufacturer’s instructions for adding
water.
Don’t mix water with ready-to-use washeruid.
Water can cause the solution to freeze and
damage your washeruid tank and other parts
of the washer system. Also, water doesn’t
clean as well as washeruid.
Fill your washeruid 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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2003 - Sonoma OM