GMC 1995 Suburban Owner's Manual page 255

6. Start the engine
and let it run until
you can feel the
upper radiator
hose getting hot.
Watch out for the
engine fan( s)
.
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 mix 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.
Be sure the
arrows
on the pressure cap line up like this.
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