Buick CENTURY 1997 Manual page 248

2. Then keep turning
the pressure cap, but
now push down as you
turn it. Remove the
pressure cap.
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. Don't spill coolant on a hot engine.
3. After the engine cools, open the coolant air bleed
valve or valves.
3100 V6 (VIN Code M): There are two bleed valves.
One is located on the thermostat housing. The other
is located on the thermostat bypass tube.
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