Hummer 2009 H3 Owner's Manual page 262

5-26 Service and Appearance Care
3. Fill the radiator with the proper
DEX-COOL coolant mixture, up
to the base of the filler neck.
See Engine Coolant on
page 5-23 for more information
about the proper coolant mixture.
4. Fill the coolant recovery tank to
the FULL COLD mark.
5. Reinstall the cap on the coolant
recovery tank, but leave the
radiator pressure cap off.
6. Start the engine and let it run
until you can feel the upper
radiator hose getting hot. Watch
out for the engine cooling fan.
7. By this time, the coolant level
inside the radiator filler neck
might 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. Then 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.