2003 Cadillac CTS Owner's Manual - Page 354

Adding Coolant If you need more coolant, add the proper DEX-COOLR coolant mixture at the surge tank, but only when the engine is cool. Surge Tank Pressure Cap NOTICE: The surge tank pressure cap is a 15 psi (103 kPa) pressure-type cap and must be tightly installed to prevent coolant loss and possible engine damage from overheating. Be sure the cap is hand-tight and fully seated. CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Don't spill coolant on a hot engine. When replacing the pressure cap, make sure it is hand-tight. 6-28