GMC 2007 Acadia - Manual (Page 413)

Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Engine Coolant Reservoir
B. Radiator Pressure Cap (covered)
C. Engine Cooling Fans
{ CAUTION:
An electric engine cooling fan under the
hood can start up even when the engine
is not running and can injure you.
Keep hands, clothing, and tools away
from any underhood electric fan.
If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
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