Cadillac 1994 DeVille Owners Literature page 248

6. Start the engine
and let it run until
you can feel the
upper radiator hose
getting hot.
Watch out for the
engine fans.
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 to the radiator
until the level reaches the base of the radiator filler neck.
8. Replace the
pressure cap. Be
sure the arrows on
the pressure cap
line up like this.