Question:How often should I replace my wiper blades?
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.
