Cadillac 2007 XLR Owner's Manual page 393

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at the FULL
COLD mark on the front of the coolant surge
tank, add a 50/50 mixture of clean, drinkable water
®
and DEX-COOL coolant at the coolant surge
tank, but be sure the cooling system, including the
coolant surge tank pressure cap, is cool before
you do it. See Engine Coolant on page 385
for more information.
If no coolant is visible in the surge tank, add
coolant as follows:
CAUTION:
{
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
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