GMC 2011 Terrain Owner's Manual page 310

10-20 Vehicle Care
WARNING
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. Do not spill
coolant on a hot engine.
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.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.
2. Keep turning the pressure cap
slowly, and remove it.
3. Fill the coolant surge tank with
the proper DEX-COOL coolant
mixture, to the COLD FILL line.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.