Cadillac 2004 DeVille - Manual (Page 307)

Checking Coolant
The engine coolant surge tank is located toward the
rear of the engine compartment on the passenger’s
side of the vehicle. For more information on location,
see Engine Compartment Overview on page 5-12.
{ CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD mark, located on the side of the surge tank
that faces the engine.
5-27