Chevrolet 2003 Impala Owner's Manual page 290

How to Add Coolant to the Radiator
The radiator pressure cap is located in the front of the
engine compartment near the diagonal cross brace
Notice: Your engine has a specific radiator on the passenger's side of the vehicle. See Engine
fill procedure. Failure to follow this procedure could
Compartment Overview
on
page 5-12 for more
cause your engine to overheat and be severely information on location. You can remove the radiator
damaged. pressure cap when the cooling system, including
P
the radiator -pressure cap and-upper radiator hose, is no
longer hot.
1. Turn the pressure cap slowly counterclockwise until
it first stops. (Don't press down while turning the
pressure cap.)
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
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