2014 Cadillac CTS Owner Manual - Page 325
2014 Cadillac CTS Manual
Page 325 highlights
Vehicle Care 10-21 { Warning Steam and scalding liquids from a hot cooling system can blow out and burn you badly. Never turn the cap when the cooling system, including the surge tank pressure cap, is hot. Wait for the cooling system and surge tank pressure cap to cool. If coolant is needed, add the proper DEX-COOL coolant mixture at the coolant surge tank. If no coolant is visible in the surge tank, add coolant as follows: 1. Remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly counterclockwise about one-quarter turn and then stop. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. 2. Keep turning the pressure cap slowly and remove it.