2013 Buick LaCrosse Owner Manual - Page 280

10-20 Vehicle Care If no coolant is visible in the coolant surge tank, add coolant as follows: { 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. How to Add Coolant to the Coolant Surge Tank 1. Turn the pressure cap slowly counterclockwise. If a hiss is heard, wait for that to stop. A hiss means there is still some pressure left. 2. Keep turning the cap and remove it. { WARNING 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. Do not spill coolant on a hot engine. Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged. The coolant surge tank pressure cap can be removed when the cooling system, including the surge tank pressure cap and upper radiator hose, is no longer hot. 3. Fill the coolant surge tank with the proper mixture to the mark pointed to on the front of the coolant surge tank.