GMC 1997 Safari Owner's Manual page 137

Brake System Warning Light
Your vehicle's hydraulic brake system is divided into
two parts. If one part isn't working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on, there could be a brake
problem. Have your brake system inspected right away.
BRAKE
This light should come
on briefly when you turn
the ignition key to RUN.
If it doesn't come on then,
have it fixed so it will be
ready to warn you if there's
a problem.
If the light comes
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 light is still on, have the
vehicle towed for service. (See "Towing Your Vehicle"
in the Index.)
I
A
CAUTION:
-
Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident. If the light is still on after you've
pulled off the road and stopped carefully, have
the vehicle towed for service.
When the ignition is on, the brake system warning light
will also come on when you set your parking brake. The
light will stay on if your parking brake doesn't release
fully. If it stays on after your parking brake is fully
released, it means you have a brake problem.