Pontiac Wave 2009 Owner's Manual page 231

2. Then keep turning the pressure cap slowly and
remove it.
3. Fill the coolant surge tank with the proper mixture to
the Maximum mark on the coolant surge tank. Wait
about five minutes, then check to see if the level is
below the mark. If the level is below the Maximum
mark, add additional coolant to bring the level up to
the mark.
Repeat this procedure until the level remains
constant at the Maximum mark for at least
five minutes.
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