Chevrolet 2002 Cavalier Owner's Manual page 225

1. Park the vehicle on a level surface. You can 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 (left) about
-
two or two and one half turns. If you hear a hiss,
wait for that to stop. This will allow any pressure
still left to be vented out the discharge hose.
5-18
2. Then keep turning the
pressure cap slowly,
and remove it.