Pontiac Grand Prix 2007 Owner's Manual page 384

So, it is not a good idea to top off the brake fluid.
Adding brake fluid will not correct a leak. If you add
fluid when the linings are worn, then you will have
too much fluid when you get new brake linings.
You should add or remove brake fluid, as
necessary, only when work is done on the
brake hydraulic system.
CAUTION:
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If your vehicle has too much brake fluid, it
can spill on the engine. The fluid will burn
if the engine is hot enough. You or others
could be burned, and your 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 Brake System
Warning Light on page 180.
384
What to Add
When you need brake fluid, use only DOT-3 brake
fluid. Use new brake fluid from a sealed container
only. See Recommended Fluids and Lubricants
on page 490.
Always clean the brake fluid reservoir cap and the
area around the cap before removing it. This
will help keep dirt from entering the reservoir.
CAUTION:
{
With the wrong kind of fluid in the brake
system, the brakes may not work well.
This could cause a crash. Always use the
proper brake fluid.