Checking Brake Fluid - GMC 2012 Sierra Denali Owner's Manual

There are only two reasons why the
brake fluid level in the reservoir
might go down:
The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
WARNING
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. See Checking Brake
Fluid in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5 24.
Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See Maintenance
Schedule on page 11 3.
Vehicle Care

Checking Brake Fluid

Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10 6.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic 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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