Chevrolet CORVETTE Owner's Manual page 251

250 Vehicle Care
How to Add Coolant to the Coolant
Surge Tank
Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
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, be sure the cooling
system is cool, then add the proper
DEX-COOL coolant mixture directly to the
surge tank.
1. Open the Hatch/Trunk. See Hatch (Boot)
0 20.
2. When the cooling system, including the
coolant surge tank pressure cap and
engine, 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.
3. Keep turning the pressure cap slowly and
remove it.
4. Fill the coolant surge tank with the
proper mixture until the level inside
stabilizes at the COLD FILL indicator in
the surge tank.
5. With the coolant surge tank pressure cap
off, start the engine and let it run until
the engine is hot.
By this time, the coolant level inside the
coolant surge tank may be lower. If the
level is lower, add more of the proper
mixture to the coolant surge tank until
the level stabilizes at the COLD FILL
indicator in the coolant surge tank.
6. Replace the pressure cap tightly.