| Answer:
Wiper blades are one of the most neglected components on vehicles
today. Many blades are cracked, split, torn, brittle, worn
or otherwise in obvious need of replacement. Others may look
okay, but do a lousy job of wiping when put to the test. Ninety
percent of all driving decisions are based on a clear unobstructed
view of the road, which means good visibility is absolutely
essential -- especially during wet weather when vision may
be obscured by water, road splash, sleet or snow on the windshield.
But good visibility requires wipers that are in good condition.
If the wipers are chattering, streaking or otherwise failing
to wipe cleanly and consistently, you need new blades -- Now!
Most experts say wiper blades should be replaced every six
to twelve months for optimum performance and driving visibility.
That's because wiper blades don't last forever. Natural rubber
deteriorates over time. Halogen-hardened rubber as well as
synthetic rubber provides longer life. But eventually all
blade materials fall victim to environmental factors. Exposure
to sunlight and ozone causes the rubber to age, even if the
wipers aren't used much. As a set of blades age, they lose
much of their flip-over flexibility and they're less able
to wipe cleanly. They may develop a permanent set (called
"parked" rubber) or curvature which prevents full
contact with the windshield. This tends to be more of a problem
on vehicles that are parked outside in the hot sun all day.
The sun bakes and hardens the rubber. Then when the wipers
are needed, they streak and chatter because they've taken
a set and won't follow the curvature of the windshield. It
can be very annoying as well as dangerous. Cold weather can
affect blade life, too. Freezing temperatures makes rubber
hard and brittle, which increases the tendency to crack and
split. The holders can also become clogged with ice and snow,
preventing the holder from distributing spring tension evenly
over the blade. The blade "freezes up" and leaves
streaks as it skips across the glass. Heavy use can be hard
on wiper blades, too, because dust, abrasives, road grime
and even bug juice wear away the edge that the blades need
to wipe cleanly. As the blade loses its edge (which is precision
cut square to maximize the squeegee effect), water gets under
the blade and remains on the glass. The result is reduced
visibility and poor wiping action. Any blade that's chattering,
streaking or doing a lousy job of wiping, therefore, is a
blade that's overdue for replacement. The same goes for any
blade that is cracked, torn, nicked or otherwise damaged.
Checking
your blades: A simple check is to try your windshield washers.
If the blades are not in good condition, you'll see why when
they attempt to wipe the washer solvent off the glass. Streaking,
chattering or any other problems will be clearly obvious.
This test also gives you the opportunity to check your windshield
washer system. Do both squirters work? If not, a nozzle may
be plugged with dirt or a hose may be kinked or loose. Does
the spray hit the windshield where it is supposed to? If not,
the nozzles need adjusting. Does the washer pump deliver an
adequate stream of solvent? If not, the vehicle may have a
weak washer pump, or a clogged, kinked or loose hose. Most
washer reservoirs have a screen to filter out debris that
could clog or damage the pump. If this screen itself is buried
under debris, it can choke off the flow of solvent to the
washers. After you've checked the windshield wipers, check
the rear wiper too if your vehicle has a rear wiper system.
Many sport utility vehicles, vans, minivans, station wagons,
hatchbacks and fastbacks do. After all, it's just as important
to see what's behind you when backing up in the rain as it
is to see what's ahead. You can use the same test (try the
rear windshield washer, if so equipped), or simply spray some
water onto the glass with a squeeze bottle and see how the
wiper performs.
Other
factors that affect your wipers: How well the wiper blades
perform also depends on the condition of the wiper arms and
holders. A blade's wiping ability is affected by the amount
of spring tension on the wiper arm, the number of pressure
points or claws that hold the blade, and the design of the
blade itself. If the springs in the arms are weak (which is
more apt to be a problem in older vehicles), the wipers may
not be pressed against the glass firmly enough to wipe cleanly.
Replacing the blades won't make any difference because the
problem is weak arms not bad blades. If the blades can be
pulled away from the glass with little resistance, it's time
for new arms. Most vehicle manufacturers publish tension specs
for their arms. If the arm doesn't meet the spec, it needs
to be replaced. Remember to check the tension on the rear
wiper arm, too, because rear wiper arms are often damaged
by drive-through car wash rollers. Wind lift is another factor
that can interfere with good wiping action at highway speeds.
Many windshields are steeply sloped to improve aerodynamics.
But steeply raked windshields with a lot of glass area direct
more wind against the wipers. This can lift the blades away
from the glass at high speed unless the wiper system and blades
are designed to counter the aerodynamic forces. Some blades
have specially designed vents and airfoils to minimize lift
and/or generate downforce to keep the blades in constant contact
with the glass as speed increases. If your original equipment blade holders need to be replaced, be sure the replacements
have the same anti-wind lift design. Another factor to keep
in mind is the design of the blade holder. A blade holder
needs to distribute the tension of the wiper arm evenly over
the blade while also allowing the blade to flex as it follows
the changing curvature of the glass. The better quality replacement
blade holders typically have six to eight claws to spread
the pressure of the wiper arm over the blade. More claws also
increases flexibility so the blades don't lose contact at
the sides of the glass.
Replacement
blades: You can usually replace wiper blades yourself, and
can replace just the blade with a refill or the entire blade
assembly. Refills will save you money. If you're installing
a blade assembly, most come with some type of adapter to fit
the arms on your vehicle. The old blades pull or push off
the arm by pressing a release button or pin on the wiper holder.
If you are replacing the blade only with a refill, the old
blade can be removed by squeezing the locking tags in at the
end of the blade so it will slip out of the holder. Make sure
the replacement blade is the same length and claw width as
the original. A blade that is too long may create interference
problems, while one that is too short may not fit the holder.
For cold weather driving, you might consider installing a
set of "winter blades" on your vehicle. These have
an enclosed holder that prevents ice and snow from building
up and interfering with the wiper's ability to do its job. |
