GMC Sierra Classic 2007 Owner's Manual page 387

And, if your tires do not have much tread left, you
will get even less traction. It is always wise to
go slower and be cautious if rain starts to fall while
you are driving. The surface may get wet
suddenly when your reflexes are tuned for driving
on dry pavement. If your vehicle has four-wheel
drive, see Four-Wheel Drive on page 151 for
transfer case mode selection.
The heavier the rain, the harder it is to see. Even
if your windshield wiper blades are in good
shape, a heavy rain can make it harder to see
road signs and traffic signals, pavement markings,
the edge of the road, and even people walking.
It is wise to keep your wiping equipment in good
shape and keep your windshield washer fluid
reservoir filled with washer fluid. Replace your
windshield wiper inserts when they show signs of
streaking or missing areas on the windshield, or
when strips of rubber start to separate from the
inserts.
CAUTION:
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Wet brakes can cause accidents. They
may not work as well in a quick stop and
may cause pulling to one side. You could
lose control of the vehicle.
After driving through a large puddle of
water or a car wash, apply the brake pedal
lightly until the brakes work normally.
Driving too fast through large water puddles or even
going through some car washes can cause
problems, too. The water may affect your brakes.
Try to avoid puddles. But if you cannot, try to slow
down before you hit them.
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