Hydraulic Brake Systems - GMC TopKick 2007 Owner's Manual

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic.
This is a mistake. The brakes may not have time to
cool between hard stops. The brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic
following distances, you will eliminate a lot of
unnecessary braking. That means better braking
and longer brake life.
If your vehicle's engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the engine stops, you will still have
some power brake assist. But you will use it
when you brake. Once the power assist is used
up, it may take longer to stop and the brake pedal
will be harder to push.

Hydraulic Brake Systems

If your engine stops running, or if your primary
brake system stops working, your vehicle
has a reserve power assist system to help you
slow down. Just slowly and steadily apply
the brake pedal until you can safely get off the
road. The pedal will seem harder to push
down. Do not pump the pedal; the system will not
work well or at all that way.
You may find that the steering wheel seems hard
to turn when you are turning and braking at
the same time. Also, the primary brake warning
light may come on and the warning tone may
sound. This is normal because the main hydraulic
brake system and power steering both use the
power steering pump.If this ever happens, let up
on the brake pedal a little. When you let up on
the brake pedal in that situation, it lets the steering
get a little more help from the pump.
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