GMC 1993 Safari Owner's Manual page 221

4. Then fill the coolant recovery tank to FULL.
I
5. Put the cap back on the coolant recovery tank, but leave the radiator
6. Start the engine and let
it
run until you can feel the upper radiator hose
7. By this time, the coolant level inside the radiator filler neck may be
pressure cap off.
getting hot. Watch out for the engine fan.
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. Be sure the arrows on the pressure cap
line up like this.
5-1 5