Pontiac 2005 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.
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
3. After the engine cools, open the coolant air bleed
valves.
5-32
Bypass Tube
There are two bleed valves. One is located on the
thermostat housing. The other is located on the
thermostat 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.
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