Chevrolet 2012 Express Owner's Manual page 272

10-22 Vehicle Care
4. Fill the coolant recovery tank to
the COLD FILL mark.
5. Reinstall the cap back on the
coolant recovery tank, but leave
the radiator pressure cap off.
6. Start the engine and let it run
until the upper radiator hose can
be felt getting hot. Watch out for
the engine cooling fan.
7. By this time, the coolant level
inside the radiator filler neck
may be lower. If the level is
lower, add more of the proper
DEX-COOL coolant mixture
through the filler neck until the
level reaches the base of the
filler neck.
8. Replace the pressure cap. At
any time during this procedure if
coolant begins to flow out of the
filler neck, reinstall the
pressure cap.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.