GMC 2002 Yukon Denali Owner's Manual page 331

CAUTION:
If you have 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. See "Checking Brake Fluid"
in this section.
Refer to the Maintenance Schedule to determine when to
check your brake fluid. See "Periodic Maintenance
Inspections" in the Index.
Checking Brake Fluid
You can check the brake fluid without taking off the cap.
Just look at the brake fluid reservoir. The fluid level
should be above MIN. If it isn't, have your brake system
checked to see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
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