Chevrolet 2005 Colorado Owner's Manual page 301

4. Then 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 may be lower. If the level is lower, add
more of the proper DEX-COOL
through the filler neck until the level reaches
the base of the filler neck.
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. Be sure to
secure it tightly.
®
coolant mixture
5-33