2005 Pontiac Aztek Owner's Manual - Page 314

2. Then keep turning the pressure cap, but now push down as you turn it. Remove the pressure cap. There are two bleed valves. One is located on the thermostat housing. The other is located on the thermostat bypass tube. {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. Do not spill coolant on a hot engine. Housing Bypass Tube 4. Fill the radiator with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 5-23 for more information about the proper coolant mixture. If you see a stream of coolant coming from an air bleed valve, close the valve. Otherwise, close the valves after the radiator is filled. 5. Rinse or wipe any spilled coolant from the engine and the compartment. 3. After the engine cools, open the coolant air bleed valves. 5-32