GMC Sierra Denali 2006 Owner's Manual page 317

What to Add
When you do 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 6-13.
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 your brake
system, your brakes may not work well,
or they may not even work at all. This could
cause a crash. Always use the proper
brake fluid.
Notice:
•
Using the wrong fluid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system parts
so badly that they will have to be replaced.
Do not let someone put in the wrong kind
of fluid.
•
If you spill brake fluid on your vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid on
your vehicle. If you do, wash it off immediately.
See Washing Your Vehicle on page 5-94.
5-37