2009 Chevrolet Equinox Owner's Manual - Page 315

Turn the pressure cap slowly counterclockwise about one-quarter of a turn. If you hear a hiss, wait for that to stop. This will allow any pressure still left to be vented out the discharge hose. 2. Then keep turning the pressure cap slowly, and remove it. 3. Fill the coolant surge tank with the proper DEX-COOL® coolant mixture, to the COLD FILL line. 4. With the coolant surge tank pressure cap off, start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fans. By this time, the coolant level inside the coolant surge tank may be lower. If the level is lower, add more of the proper DEX-COOL® coolant mixture to the coolant surge tank until the level reaches the COLD FILL line. 5-27