GMC 2003 GMT560 T-Series, Owner'S Manual, Page: 90 / 284

Brake System Warning Light
Your vehicle has either hydraulic or air brakes. Each
system has different warning lights.
Hydraulic Brake System Warning
Lights
Vehicles with hydraulic brake systems have two brake
system warning lights on the instrument panel.
If the BRAKE warning light
comes on, it means that
the fluid level in the master
cylinder reservoir is low
or there is another problem
with your hydraulic
brakes.
When it comes on, you will also hear a warning tone.
The BRAKE warning light may come on, and the
warning tone may sound, when you’re turning and
braking at the same time. This is normal. See
Hydraulic
Brake Systems under Braking on page 4-6.
If the amber service
brakes soon warning light
comes on, it means
there is something wrong
in the brake system.
When this light comes on, you will also hear a warning
tone. If this light comes on, have the system repaired
immediately.
Both of these lights should come on briefly every time
you start your engine. If they don’t come on then,
have them fixed so they will be ready to warn you if
there’s a problem. If one or both of these warning lights
stay on after you start the engine, there could be a
brake problem. Have your brake system inspected
right away.
If one or both of these lights come on while you are
driving, pull off the road and stop carefully. You
may notice that the pedal is harder to push. Or, the
pedal may go closer to the floor. It may take longer to
stop. If the BRAKE light is still on, have the vehicle
towed for service. See
Towing Your Vehicle on
page 4-32. See Hydraulic Brake Systems under Braking
on page 4-6 for further information.
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