Buick 2009 Lucerne - Manual (Page 318)

How to Add Coolant to the Radiator
{ CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{ CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They are
under pressure, and if you turn the surge tank
pressure cap — even a little — they can come out
at high speed. Never turn the cap when the cooling
system, including the surge tank pressure cap, is
hot. Wait for the cooling system and surge tank
pressure cap to cool if you ever have to turn the
pressure cap.
If coolant is needed, add the proper mixture directly to
the radiator, but be sure the cooling system is cool
before this is done.
1. You can remove the
pressure cap when
the cooling system,
including the pressure
cap and upper
radiator hose is no
longer hot. Turn the
pressure cap slowly
counterclockwise.
2. If you hear a hiss, wait for that to stop. A hiss
means that there is still some pressure left.
Keep turning the pressure cap and remove it.
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