Cadillac 2011 CTS Coupe Owner's Manual page 351

If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See
.
Use only new DOT 3 brake fluid
from a sealed container. See
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.
With the wrong kind of fluid in
the brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid.
.