Buick 2009 Enclave Owner's Manual page 300

How to Add Coolant to the Cooling
System (5.3L V8 Engine)
If you hear a hiss, wait for that to stop. A hiss
means that there is still some pressure left.
2. Then keep turning the pressure cap and remove it.
3. Fill the cooling system with the proper DEX-COOL
coolant mixture, up to the base of the filler neck.
See Engine Coolant on page 5-25 Engine Coolant
Engine Coolant for more information about the
proper coolant mixture.
4. Rinse or wipe any spilled coolant from the engine
and the compartment.
5-30
1. You can remove the
pressure cap when
the cooling system,
including the pressure
cap and upper radiator
hose is no longer
hot. Turn the
pressure cap slowly
counterclockwise.
5. Then fill the coolant recovery tank to the
COLD FILL line.
6. Install the coolant recovery tank cap and the
pressure cap. After a day or two of driving, when the
®
engine is cold, check the coolant level in the recovery
tank. If it is low, refill it to the COLD FILL line.
If the coolant in the recovery tank is constantly low,
you should have a dealer/retailer service department
inspect the vehicle for leaks.