GMC 1996 Savana Van Owner's Manual page 206

5. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.
I
.,
.
k.
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine fan.
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.
7. By this time the coolant level inside the radiator
5-18