SUBARU IMPREZA WRX STI 2012 Owners Manual

Black plate (343,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
Air cleaner element
WARNING
Do not operate the engine with the
air cleaner element removed. The air
cleaner element not only filters
intake air but also stops flames if
the engine backfires. If the air
cleaner element is not installed
when the engine backfires, you
could be burned.
CAUTION
When replacing the air cleaner ele-
ment, use a genuine SUBARU air
cleaner element. If it is not used,
there is the possibility of causing a
negative effect to the engine.
The air cleaner element functions as a
filter screen. When the element is perfo-
rated or removed, engine wear will be
excessive and engine life shortened.
It is not necessary to clean or wash the air
cleaner element.
& Replacing the air cleaner
elementReplace the air cleaner element according
to the maintenance schedule in the
“Warranty and Maintenance Booklet ”. Un-
der extremely dusty conditions, replace it
more frequently. It is recommended that
you always use genuine SUBARU parts.1. Use a screwdriver to undo the clips on
the air intake duct, then remove the air
intake duct.
1) Connector
2) Clip2. Unplug the connector that is attached
to the top of the air cleaner case.
3. Unsnap the two clips holding the air
cleaner case cover.
Maintenance and service
11-13
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11

Black plate (344,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
11-14
Maintenance and service
4. Open the air cleaner case and remove
the air cleaner element.
5. Clean the inside of the air cleaner case
and case cover with a damp cloth and
install a new air cleaner element.6. If the air cleaner case has been
removed, insert the three projections on
the air cleaner case into the slits on the air
cleaner case cover.
7. Install in the reverse order of removal.
Spark plugsIt may be difficult to replace the spark
plugs. It is recommended that you have
the spark plugs replaced by your
SUBARU dealer.
The spark plugs should be replaced
according to the maintenance schedule
in the “Warranty and Maintenance Book-
let ”.
CAUTION
. When disconnecting the spark
plug cables, always grasp the
spark plug cap, not the cables.
. Make sure the cables are re-
placed in the correct order.
& Recommended spark plugsFor the recommended spark plugs, refer
to“Electrical system ”F 12-3.

Black plate (345,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
Drive belts1) Power steering oil pump pulley
2) Front side belt
3) Alternator pulley
4) Air conditioner compressor pulley
5) Rear side belt
6) Crank pulley
A) 22 lbf (98 N, 10 kgf)
CAUTION
The front side belt, which runs in
conjunction with the following com-
ponents, must be used within the
specified deflection.
. Power steering oil pump pulley
. Alternator pulley
. Crank pulley Check the deflection of the front
side belt and if there is any loosen-
ess, cracks, wear or unusual noise
on the front side belt, contact your
SUBARU dealer.
Continuing to use the vehicle with
the belt outside of the specification
may cause the engine to malfunc-
tion and the above components to
malfunction.
To check the deflection of the front side
belt, place a straightedge (ruler) across
two adjacent pulleys (alternator pulley and
crank pulley) and apply a force of 22 lbf
(98 N, 10 kgf) midway between the pulleys
by using a spring scale. The belt deflec-
tion should be the amount specified. If the
front side belt is loose, cracked or worn,
contact your SUBARU dealer.
in (mm)
Deflection
New belt Used belt
A 0.28
–0.35
(7.0 –9.0) 0.35
–0.43
(9.0 –11.0)
The rear side belt is a stretch-type belt,
therefore the deflection does not need to
be checked. If there are cracks or wear
confirmed on the belts and a squeaking
noise is heard from them, contact your
SUBARU dealer.
Manual transmission oil& Checking the oil levelExcept STICheck the oil level monthly.
1. Park the vehicle on a level surface and
stop the engine.
2. Pull out the level gauge, wipe it clean,
and insert it again.
Maintenance and service
11-15
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11

Black plate (346,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
11-16
Maintenance and service
1) Upper level
2) Lower level3. Pull out the level gauge again and
check the oil level on it. If it is below the
lower level, add oil through the level
gauge hole to bring the level up to the
upper level.
CAUTION
Be careful not to spill manual trans-
mission oil when adding it. If oil
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or a
fire. If oil gets on the exhaust pipe,
be sure to wipe it off.NOTEThere is no transmission oil level
gauge for STI. Consult your SUBARU
dealer to check the oil level.& Recommended grade and
viscosityEach oil manufacturer has its own base
oils and additives. Never use different
brands together. For details, refer to
“Manual transmission and rear differential
gear oil ”F 12-6.
Rear differential gear oilThere is no rear differential gear oil level
gauge. To check the rear differential gear
oil level, we recommend that you consult
your SUBARU dealer for inspection.& Recommended grade and
viscosityEach oil manufacturer has its own base
oils and additives. Never use different
brands together. For details, refer to
“Manual transmission and rear differential
gear oil ”F 12-6.

Black plate (347,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
Power steering fluid& Checking the fluid levelThe power steering fluid expands greatly
as its temperature rises; the fluid level
differs according to fluid temperature.
Therefore, the reservoir tank has two
different checking ranges for hot and cold
fluids.
Check the power steering fluid level
monthly.
1. Park the vehicle on a level surface,
and stop the engine.
2. Check the fluid level of the reservoir
tank.
When the fluid is hot after the vehicle has
been run: Check that the oil level is
between “HOT MIN ”and “HOT MAX ”on
the surface of the reservoir tank.
When the fluid is cool before the vehicle is
run: Check that the oil level is between
“COLD MIN ”and “COLD MAX ”on the
surface of the reservoir tank.
3. If the fluid level is lower than the
applicable “MIN ”line, add the recom-
mended fluid as necessary to bring the
level between the “MIN”and “MAX ”line.
If the fluid level is extremely low, it may
indicate possible leakage. Consult your
SUBARU dealer for an inspection.
WARNING
Be careful not to burn yourself
because the fluid may be hot.
CAUTION
. When power steering fluid is
being added, use only clean fluid,
and be careful not to allow any
dirt into the tank. And never use
different brands together.
. Be careful not to spill power
steering fluid when adding it. If
power steering fluid touches the
exhaust pipe, it may cause a bad
smell, smoke, and/or a fire. If
power steering fluid gets on the
exhaust pipe, be sure to wipe it
off.& Recommended fluidRefer to “Fluids”F 12-7.
Maintenance and service
11-17
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Black plate (348,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
11-18
Maintenance and service
Brake fluid& Checking the fluid level1) “MAX ”level mark
2) “MIN ”level markCheck the fluid level monthly.
Check the fluid level on the outside of the
reservoir. If the level is below “MIN”, add
the recommended brake fluid to “MAX”.
Use only brake fluid from a sealed
container.
WARNING
. Never let brake fluid contact your
eyes because brake fluid can be
harmful to your eyes. If brake
fluid gets in your eyes, immedi-
ately flush them thoroughly with clean water. For safety, when
performing this work, wearing
eye protection is advisable.
. Brake fluid absorbs moisture
from the air. Any absorbed moist-
ure can cause a dangerous loss
of braking performance.
. If the vehicle requires frequent
refilling, there may be a leak. If
you suspect a problem, have the
vehicle checked at your SUBARU
dealer.
CAUTION
. When adding brake fluid, be care-
ful not to allow any dirt into the
reservoir.
. Never splash the brake fluid over
painted surfaces or rubber parts.
Alcohol contained in the brake
fluid may damage them.
. Be careful not to spill brake fluid
when adding it. If brake fluid
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or
a fire. If brake fluid gets on the
exhaust pipe, be sure to wipe it
off.
& Recommended brake fluidRefer to “Fluids”F 12-7.
CAUTION
Never use different brands of brake
fluid together. Also, avoid mixing
DOT 3 and DOT 4 brake fluids even if
they are the same brand.

Black plate (349,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
Clutch fluid& Checking the fluid levelCheck the fluid level on the outside of the
reservoir. If the level is below “MIN”level
mark, add the recommended clutch fluid
to “MAX ”level mark.
Use only clutch fluid from a sealed
container.
WARNING
Never let clutch fluid contact your
eyes because clutch fluid can be
harmful to your eyes. If clutch fluid
gets in your eyes, immediately flush
them thoroughly with clean water.
For safety, when performing this
work, wearing eye protection is advisable.
CAUTION
.
Clutch fluid absorbs moisture
from the air. Any absorbed moist-
ure can cause improper clutch
operation.
. If the vehicle requires frequent
refilling, there may be a leak. If
you suspect a problem, have the
vehicle checked at your SUBARU
dealer.
. When clutch fluid is added, be
careful not to allow any dirt into
the tank.
. Never splash the clutch fluid over
painted surfaces or rubber parts.
Alcohol contained in the clutch
fluid may damage them.
. Be careful not to spill clutch fluid
when adding it. If clutch fluid
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or
a fire. If clutch fluid gets on the
exhaust pipe, be sure to wipe it
off.
& Recommended clutch fluidRefer to “Fluids”F 12-7.
CAUTION
Never use different brands of clutch
fluid together. Also, avoid mixing
DOT 3 and DOT 4 brake fluids even if
they are the same brand.
Maintenance and service
11-19
11

Black plate (350,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
11-20
Maintenance and service
Brake boosterIf the brake booster does not operate as
described in the following, have it checked
by your SUBARU dealer.
1. With the engine off, depress the brake
pedal several times, applying the same
pedal force each time. The distance the
pedal travels should not vary.
2. With the brake pedal depressed, start
the engine. The pedal should move
slightly down to the floor.
3. With the brake pedal depressed, stop
the engine and keep the pedal depressed
for 30 seconds. The pedal height should
not change.
4. Start the engine again and run for
approximately one minute then turn it off.
Depress the brake pedal several times to
check the brake booster. The brake
booster operates properly if the pedal
stroke decreases with each depression.NOTEFor vehicles equipped with the brake
assist system, when you depress the
brake pedal strongly or suddenly, you
might feel that lighter depression of the
brake pedal generates a greater brak-
ing force. However, even though these
occur, they do not indicate any mal- functions, and the brake assist system
is operating properly.
Brake assist is not a system that brings
more braking ability to the vehicle
beyond its breaking capability.
Brake pedalCheck the brake pedal free play and
reserve distance according to the main-
tenance schedule in the
“Warranty and
Maintenance Booklet ”.&Checking the brake pedal
free play1) 0.02 –0.08 in (0.5 –2.0 mm)Stop the engine and firmly depress the
brake pedal several times. Lightly pull the
brake pedal up with one finger to check
the free play with a force of less than 2 lbf
(10 N, 1 kgf).
If the free play is not within proper
specification, contact your SUBARU deal-
er.

Black plate (351,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
& Checking the brake pedal
reserve distance1) More than 2.56 in (65 mm)Depress the pedal with a force of approxi-
mately 66 lbf (294 N, 30 kgf) and measure
the distance between the upper surface of
the pedal pad and the floor.
When the measurement is smaller than
the specification, or when the pedal does
not operate smoothly, contact with your
SUBARU dealer.
Clutch pedalCheck the clutch pedal free play and
reserve distance according to the main-
tenance schedule in the “Warranty and
Maintenance Booklet ”.&Checking the clutch functionCheck the clutch engagement and disen-
gagement.
1. With the engine idling, check that there
are no abnormal noises when the clutch
pedal is depressed, and that shifting into
1st or reverse feels smooth.
2. Start the vehicle by releasing the pedal
slowly to check that the engine and
transmission smoothly couple without
any sign of slippage.
&Checking the clutch pedal
free play1) 0.16 –0.43 in (4.0 –11.0 mm)Lightly depress the clutch pedal down with
your finger until you feel resistance, and
check the free play.
If the free play is not within proper
specification, contact your SUBARU deal-
er.
Maintenance and service
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11

Black plate (352,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
11-22
Maintenance and service
Hill start assist systemEnsure that the Hill start assist system
operates properly under the following
circumstances:
1. Stop the vehicle on an uphill grade by
depressing the brake pedal and clutch
pedal, with the engine running.
2. Make sure that the vehicle does not
move backward even after the brake
pedal is released.
3. Then make sure the vehicle starts
climbing the grade by following the normal
starting procedures.
If the Hill start assist system does not
operate as described above, contact with
your SUBARU dealer.
Replacement of brake pad
and liningThe disc brakes have audible wear
indicators on the brake pads. If the brake
pads wear close to their service limit, the
wear indicator makes a very audible
scraping noise when the brake pedal is
applied.
If you hear this scraping noise each time
you apply the brake pedal, have the brake
pads serviced by your SUBARU dealer as
soon as possible.
CAUTION
If you continue to drive despite the
scraping noise from the audible
brake pad wear indicator, it will result in the need for costly brake
rotor repair or replacement.
&
Breaking-in of new brake
pads and liningsWhen replacing the brake pad or lining,
use only genuine SUBARU parts. After
replacement, the new parts must be
broken in as follows.
! Brake pad and lining
While maintaining a speed of 30 to 40
mph (50 to 65 km/h), step on the brake
pedal lightly. Repeat this five or more
times.
! Parking brake lining
1. Drive the vehicle at a speed of
approximately 22 mph (35 km/h).
2. With the parking brake release button
pushed in, pull the parking brake lever
SLOWLY and GENTLY (pulling with a
force of approximately 33.7 lbf [150 N,
15.3 kgf]).
3. Drive the vehicle for approximately
220 yards (200 meters) in this condition.
4. Wait 5 to 10 minutes for the parking
brake to cool down. Repeat this proce-
dure.
5. Check the parking brake stroke. If the
parking brake stroke is out of the specified