GMC Sierra Denali Classic 2007 Owner's Manual page 281

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.
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:
{
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 your brake pedal
lightly until your 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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