Chevrolet Corvette Owner's Manual page 228

Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to jet out at high speed and you
could be burned. Never turn the
cap when the cooling system,
including the pressure cap itself,
is hot. Wait for the cooling system
and pressure cap to cool.
If coolant is needed, add the proper
DEX-COOL coolant mixture directly
to the surge tank but be sure the
cooling system is cool before this
is done.
1. When the cooling system,
including the coolant surge
tank pressure cap and upper
radiator hose, is no longer hot,
remove the pressure cap.
Turn the pressure cap slowly
anticlockwise about
one-quarter turn and then stop.
If a hiss is heard, wait for that
to stop. A hiss means there is
still some pressure left.
2. Keep turning the pressure cap
slowly and remove it.
3. Fill the coolant surge tank with
the proper mixture until the
level inside stabilises at the
cold fill line on the front of the
surge tank.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Any time during
this procedure, watch out for
the engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
Vehicle Care
lower, add more of the proper
mixture to the coolant surge
tank until the level stabilises at
the cold fill line on the coolant
surge tank.
5. Replace the pressure cap
tightly.
6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 6.
If the coolant still is not at the
proper level when the system
cools down again, see your
dealer.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
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