2007 SUBARU IMPREZA maintenance

tread separation, and destruction of
the tires. The resulting loss of
vehicle control could lead to anaccident.
& Wheel balance
Each wheel was correctly balanced when
your vehicle was new, but the wheels will
become unbalanced as the tires become
worn during use. Wheel imbalance causes
the steering wheel to vibrate slightly at
certain vehicle speeds and detracts from
the vehicle ’s straight-line stability. It can
also cause steering and suspension sys-
tem problems and abnormal tire wear. If
you suspect that the wheels are not
correctly balanced, have them checked
and adjusted by your SUBARU dealer.
Also have them adjusted after tire repairs
and after tire rotation. NOTE
Loss of correct wheel alignment*
causes the tires to wear on one side
and reduces the vehicle ’s running
stability. Contact your SUBARU dealer
if you notice abnormal tire wear.
*: The suspension system is designed to hold
each wheel at a certain alignment (relative to
the other wheels and to the road) for optimum
straight-line stability and cornering perfor- mance.
& Wear indicators
1) New tread
2) Worn tread
3) Tread wear indicator
Each tire incorporates a tread wear
indicator, which becomes visible when
the depth of the tread grooves decreases
to 0.063 in (1.6 mm). A tire must be
replaced when the tread wear indicator
appears as a solid band across the tread.
WARNING
When a tire ’s tread wear indicator
becomes visible, the tire is worn
beyond the acceptable limit and
must be replaced immediately. With a tire in this condition, driving at
high speeds in wet weather can
cause the vehicle to hydroplane.
The resulting loss of vehicle control
can lead to an accident.
NOTE
For safety, inspect tire tread regularly
and replace the tires before their tread
wear indicators become visible. & Tire rotation direction markExample of tire rotation direction mark
1) Front
If the tire has the rotation direction
specification, the tire rotation direction
mark is placed on its sidewall. Maintenance and service
11-33
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11-34Maintenance and service
When you install a tire that has the tire
rotation direction mark, install the tire with
the direction mark facing forward. & Tire rotation
Vehicles equipped with unidirectional tires
1) Front
Vehicles equipped with 4 non-unidirec-
tional tires
1) Front
Tire wear varies from wheel to wheel. To
maximize the life of each tire and ensure
that the tires wear uniformly, it is best to
rotate the tires every 7,500 miles (12,500
km). Move the tires to the positions shown
in the illustration each time they arerotated.
Replace any damaged or unevenly worn
tires at the time of rotation. After tire
rotation, adjust the tires pressures and
make sure the wheel nuts are correctlytightened.
After driving approximately 600 miles
(1,000 km), check the wheel nuts again
and retighten any nut that has become loose. &
Tire replacement
The wheels and tires are important and
integral parts of your vehicle ’s design;
they cannot be changed arbitrarily. The
tires fitted as standard equipment are
optimally matched to the characteristics
of the vehicle and were selected to give
the best possible combination of running
performance, ride comfort, and service
life. It is essential for every tire to have a
size and construction matching those
shown on the tire placard and to have a
speed symbol and load index matching
those shown on the tire placard.
Using tires of a non-specified size detracts
from controllability, ride comfort, braking
performance, speedometer accuracy and
odometer accuracy. It also creates incor-
rect body-to-tire clearances and inappro-
priately changes the vehicle ’s ground
clearance.
All four tires must be the same in terms of
manufacturer, brand (tread pattern), con-
struction, and size. You are advised to
replace the tires with new ones that are
identical to those fitted as standard equip-ment.
For safe vehicle operation, SUBARU

recommends replacing all four tires at the
same time.
WARNING
. All four tires must be the same in
terms of manufacturer, brand
(tread pattern), construction, de-
gree of wear, speed symbol, load
index and size. Mixing tires of
different types, sizes or degrees
of wear can result in damage tovehicle ’s powertrain. Use of dif-
ferent types or sizes of tires can
also dangerously reduce con-
trollability and braking perfor-
mance and can lead to an acci- dent.
. Use only radial tires. Do not use
radial tires together with belted
bias tires and/or bias-ply tires.
Doing so can dangerously re-
duce controllability, resulting in
an accident.
& Wheel replacement
When replacing wheels due, for example,
to damage, make sure the replacement
wheels match the specifications of the
wheels that are fitted as standard equip-
ment. Replacement wheels are available from SUBARU dealers.WARNING
Use only those wheels that are
specified for your vehicle. Wheels
not meeting specifications could
interfere with brake caliper opera-
tion and may cause the tires to rub
against the wheel well housing dur-
ing turns. The resulting loss of
vehicle control could lead to anaccident.
NOTE
When any of the wheels are removed
and replaced for tire rotation or to
change a flat tire, always check the
tightness of the wheel nuts after driv-
ing approximately 600 miles (1,000 km).
If any nut is loose, tighten it to the
specified torque. Aluminum wheels
Aluminum wheels can be scratched and
damaged easily. Handle them carefully to
maintain their appearance, performance,
and safety. .
When any of the wheels are removed
and replaced for tire rotation or to change
a flat tire, always check the tightness of
the wheel nuts after driving approximately
600 miles (1,000 km). If any nut is loose,
tighten it to the specified torque. . Never apply oil to the threaded parts,
wheel nuts, or tapered surface of the wheel. . Never let the wheel rub against sharp
protrusions or curbs.. Be sure to fit tire chains on uniformly
and completely around the tire, otherwise
the chains may scratch the wheel. . When wheel nuts, balance weights, or
the center cap is replaced, be sure to
replace them with genuine SUBARU parts
designed for aluminum wheels. Maintenance and service
11-35

11-36Maintenance and service
Intercooler water spray (WRX-STI)
Add water to the intercooler water spray
tank when the intercooler water spray
warning light in the combination meter
comes on. The warning light comes on
when the water in the tank has decreased
to approximately 0.4 liters (0.4 US qt, 0.4
Imp qt).
The tank is located on the right-hand side
of the trunk. NOTE .Use only pure water for refilling.
. In cold weather (when you do not
use the intercooler water spray), keep
the tank half-empty in case the water
freezes. A larger amount of water could
break the tank if it froze. Windshield washer fluid
If you spray washer fluid on the windshield
but the supply of washer fluid appears to
diminish, check the level of washer fluid in
the tank.

Washer fluid level gauge
Remove the washer tank filler cap, then
check the fluid level indicated by the level
gauge (attached to the inside of the cap).
If the level is near the“Low ”mark, add
fluid until it reaches the “Hi ”level on the level gauge or the
“FULL ”mark on the
tank.
Use windshield washer fluid. If windshield
washer fluid is unavailable use clean
water.
In areas where water freezes in winter,
use an anti-freeze type windshield washer
fluid. SUBARU Windshield Washer Fluid
contains 58.5% methyl alcohol and 41.5%
surfactant, by volume. Its freezing tem-
perature varies according to how much it
is diluted, as indicated in the followingtable.
Washer Fluid
Concentration Freezing
Temperature
30% 10.48F( 12 8C)
50% 48F( 20 8C)
100% 49 8F( 45 8C)
CAUTION
Never use engine coolant as washer
fluid because it could cause paintdamage.
In order to prevent freezing of washer
fluid, check the freezing temperatures in
the table above when adjusting the fluid
concentration to the outside temperature.
If you fill the reservoir tank with a fluid with a different concentration from the one
used previously, purge the old fluid from
the piping between the reservoir tank and
washer nozzles by operating the washer
for a certain period of time. Otherwise, if
the concentration of the fluid remaining in
the piping is too low for the outside
temperature, it may freeze and block thenozzles.
CAUTION
Adjust the washer fluid concentra-
tion appropriately for the outside
temperature. If the concentration is
inappropriate, sprayed washer fluid
may freeze on the windshield and
obstruct your view, and the fluid
may freeze in the reservoir tank. Maintenance and service
11-37

11-38Maintenance and service
Replacement of wiper blades
Grease, wax, insects, or other material on
the windshield or the wiper blade results in
jerky wiper operation and streaking on the
glass. If you cannot remove the streaks
after operating the windshield washer or if
the wiper operation is jerky, clean the
outer surface of the windshield (or rear
window) and the wiper blades using a
sponge or soft cloth with a neutral
detergent or mild-abrasive cleaner. After
cleaning, rinse the windshield and wiper
blades with clean water. The windshield is
clean if beads do not form when you rinse
the windshield with water.
CAUTION
Do not clean the wiper blades with
gasoline or a solvent, such as paint
thinner or benzene. This will cause
deterioration of the wiper blades.
If you cannot eliminate the streaking even
after following this method, replace the
wiper blades using the following proce-dures: &
Windshield wiper blade as- sembly
1. Raise the wiper arm off the windshield.1) Stopper
2. Remove the wiper blade assembly by
holding its pivot area and pushing it in the
direction shown by the arrow while de-
pressing the wiper blade stopper.
3. Install the wiper blade assembly to the
wiper arm. Make sure that it locks in place.
4. Hold the wiper arm by hand and slowly
lower it in position. &
Windshield wiper blade rub- ber
1) Metal support
1. Grasp the locked end of the blade
rubber assembly and pull it firmly until the
stoppers on the rubber are free of the
metal support.

1) Metal spines
2. If the new blade rubber is not provided
with two metal spines, remove the metal
spines from the old blade rubber and
install them in the new blade rubber.
3. Align the claws of the metal support with the grooves in the rubber and slide
the blade rubber assembly into the metal
support until it locks.
1) Stopper
4. Be sure to position the claws at the
end of the metal support between the
stoppers on the rubber as shown. If the
rubber is not retained properly, the wiper
blade may scratch the windshield. &
Rear window wiper blade assembly
1. Raise the wiper arm off the rear
window.
2. Turn the wiper blade assembly coun- terclockwise. Maintenance and service
11-39
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11-40Maintenance and service
3. Pull the wiper blade assembly toward
you to remove it from the wiper arm. &Rear window wiper blade rubber
1. Pull out the end of the blade rubber
assembly to unlock it from the plasticsupport.
2. Pull the blade rubber assembly out of
the plastic support.
1) Metal spines 3. If the new blade rubber is not provided
with two metal spines, remove the metal
spines from the old blade rubber and
install them in the new blade rubber.
4. Align the claws of the plastic support
with the grooves in the blade rubber
assembly, then slide the blade rubber
assembly into place.