Pontiac 1999 Firebird Owner's Manual page 230

4. Fill the radiator with the proper DEX
coolant mixture, up to the base of the filler neck.
(See "Engine Coolant" in the Index for more
information about the proper coolant mixture.)
If you see a stream of coolant coming from an air
bleed valve, close the valve. Otherwise, close the
valve after the radiator is filled.
5-20
R
-
COOL 5. Then fill the coolant recovery tank to the
FULL COLD mark.
6. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.
yellowblue