2003 SUBARU IMPREZA brake

Appearance care
10-4
Corrosion protection
Your SUBARU has been designed and built to resist
corrosion. Special materials and protective finishes
have been used on most parts of the vehicle to help
maintain fine appearance, strength, and reliable op- eration. Most common causes of corrosion
The most common causes of corrosion are:
1. The accumulation of moisture retaining dirt and
debris in body panel sections, cavities, and other
areas.
2. Damage to paint and other protective coatings caused by gravel and stone chips or minor acci- dents.
Corrosion is accelerated on the vehicle when:
1. It is exposed to road salt or dust control chemi-
cals, or used in coastal areas where there is more
salt in the air, or in areas where there is considerable industrial pollution.
2. It is driven in areas of high humidity, especially
when temperatures range just above freezing.
3. Dampness in certain parts of the vehicle remains
for a long time, even though other parts of the ve-
hicle may be dry. 4. High temperatures will cause corrosion to parts
of the vehicle which cannot dry quickly due to lack
of proper ventilation.
To help prevent corrosion
Wash the vehicle frequently. If you drive on salted
roads in the winter or if you live in a coastal area,
you should flush the underbody with fresh water fre-
quently.
After the winter has ended, it is recommended that
the underbody be given a very thorough washing.
Before the beginning of winter, check the condition of underbody components, such as the exhaust sys- tem, fuel and brake lines, brake cables, suspension, steering system, floor pan, and fenders. If any of
them are found to be rusted, they should be given
an appropriate rust prevention treatment or should
be replaced. Contact your SUBARU dealer to per-
form this kind of maintenance and treatment if you need assistance. Repair chips and scratches in the paint as soon as you find them.
Check the interior of the vehicle for water and dirt
accumulation under the floor mats because that
could cause corrosion. Occasionally check under

11
11-1
– CONTINUED –
Maintenance schedule 11-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance precautions 11-3 . . . . . . . . . . . . . . . . . . . . . . . .
Engine hood 11-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment overview 11-8 . . . . . . . . . . . . . . . . .
2.5 liter model 11-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 liter (Turbo) model 11-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the oil and oil filter 11-11 . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-13 . . . . . . . . . . .
Recommended grade and viscosity under
severe driving conditions 11-15 . . . . . . . . . . . . . . . . . . . . . .
Synthetic oil 11-15
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 11-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan, hose and connections 11-16 . . . . . . . . . . . .
Engine coolant 11-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air cleaner element 11-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the air cleaner element 11-20 . . . . . . . . . . . . . .
Spark plugs 11-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended spark plugs 11-24 . . . . . . . . . . . . . . . . . . . . .
Drive belts 11-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission oil 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-26 . . . . . . . . . . .
Automatic transmission fluid 11-27 . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front differential gear oil (AT vehicles) 11-29
. . . . .
Checking the oil level 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-30 . . . . . . . . . . .
Rear differential gear oil 11-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the gear oil level 11-31 . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-32 . . . . . . . . . . .
Power steering fluid 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . .
Clutch fluid (MT vehicles) 11-35 . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended clutch fluid 11-36 . . . . . . . . . . . . . . . . . . . . . .
Brake booster 11-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal 11-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the brake pedal free play 11-37 . . . . . . . . . . . .
Checking the brake pedal reserve distance 11-37 . .
Clutch pedal (MT vehicles) 11-38 . . . . . . . . . . . . . . . . . . . . . .
Checking the clutch function 11-38 . . . . . . . . . . . . . . . . . . . .
Checking the clutch pedal free play 11-38 . . . . . . . . . . .
Replacement of brake pad and lining 11-39 . . . . . . . .
Breaking-in of new brake pads and linings 11-39 . . .
Parking brake stroke 11-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and wheels 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and service

Maintenance and service
11-4
Always be very careful to avoid injury when
working on the vehicle. Remember that some of the materials in the vehicle may be hazard-
ous if improperly used or handled, for exam-ple, battery acid. Your vehicle should only be serviced by per-
sons fully competent to do so. Serious per-sonal injury may result to persons not experi-enced in servicing vehicles. Always use the proper tools and make cer-
tain that they are well maintained. Never get under the vehicle supported only
by a jack. Always use a safety stands to sup-port the vehicle. Never keep the engine running in a poorly
ventilated area, such as a garage or other
closed areas. Do not smoke or allow open flames around
the fuel or battery. This will cause a fire. Because the fuel system is under pressure,
replacement of the fuel filter should be per-
formed only by your SUBARU dealer. Wear adequate eye protection to guard
against getting oil or fluids in your eyes. If something does get in your eyes, thoroughly
wash them out with clean water. Do not tamper with the wiring of the SRS airbag system or seatbelt pretensioner sys-tem, or attempt to take its connectors apart,as that may activate the system or it can ren-der it inoperative. The wiring and connectorsof these systems are yellow for easy identifi-cation. NEVER use a circuit tester for these wiring. If your SRS airbag or seatbelt pretensionerneeds service, consult your nearest SUBARU
dealer.
Before checking or servicing in the
engine compartment
Always stop the engine and set the parking
brake firmly to prevent the vehicle from mov- ing. Always let the engine cool down. Engine
parts become very hot when the engine is run-
ning and remain hot for some time after theengine is stopped. Do not spill engine oil, engine coolant, brake
fluid or any other fluid on hot engine compo-nents. This may cause a fire. Always remove the key from the ignition
switch. When the ignition switch is in the
“ON” position, the cooling fan may operate

Maintenance and service
11-8
Engine compartment overview 2.5 liter model
1) Manual transmission oil level gauge
(MT) (page 11-25) or Differential
gear oil level gauge (AT) (page 11-29)
2) Air cleaner element (page 11-20)
3) Clutch fluid reservoir (page 11-35)
4) Automatic transmission fluid level gauge (page 11-27)
5) Brake fluid reservoir (page 11-34)
6) Windshield washer tank (page
11-50)
7) Fuse box (page 11-56)
8) Battery (page 11-54)
9) Engine oil filler cap (page 11-10)
10) Engine coolant reservoir (page 11-16)
11) Radiator cap (page 11-16)
12) Engine oil level gauge (page 11-10)
13) Power steering fluid reservoir (page 11-32)

Maintenance and service
11-9
– CONTINUED –
2.0 liter (Turbo) model
1) Manual transmission oil level
gauge (MT) (page 11-25) or
Differential gear oil level gauge
(AT) (page 11-29)
2) Air cleaner element (page 11-20)
3) Clutch fluid reservoir (page
11-35)
4) Automatic transmission fluid level gauge (page 11-27)
5) Brake fluid reservoir (page
11-34)
6) Windshield washer tank (page
11-50)
7) Fuse box (page 11-56)
8) Battery (page 11-54)
9) Engine oil filler cap (page 11-10)
10) Engine coolant reservoir (page
11-16)
11) Engine oil level gauge (page 11-10)
12) Radiator cap (page 11-16)
13) Power steering fluid reservoir (page 11-32)

Maintenance and service
11-27
– CONTINUED –
SAE viscosity No. and Applicable Temperature Automatic transmission fluid
Checking the fluid level
The automatic transmission fluid expands largely as
its temperature rises; the fluid level differs according
to fluid temperature. Therefore, there are two differ-ent scales for checking the level of hot fluid andcold fluid on the dipstick.
Though the fluid level can be checked without
warming up the fluid on the “COLD” range, we rec-
ommend checking the fluid level when the fluid is at
operating temperature.
Checking the fluid level when the fluid is hot
Check the fluid level monthly.
1. Drive the vehicle several miles to raise the tem-
perature of the transmission fluid up to normal oper-
ating temperature; 158 to 176 °F (70 to 80 °C) is nor-
mal.
2. Park the vehicle on a level surface and set theparking brake.
3. First shift the selector lever in each position. Then shift it in the “P” position, and run the engine at id-
ling speed.

Maintenance and service
11-34
Brake fluid Checking the fluid level
1) “MAX” level mark
2) “MIN” level mark
Check 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
Brake fluid absorbs moisture from the air.
Any absorbed moisture can cause a danger- ous 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
Never use different brands of brake fluid to-
gether. When adding brake fluid, be careful not to
allow any dirt into the reservoir. Never splash the brake fluid over painted
surfaces or rubber parts. Alcohol contained inthe brake fluid may damage them.
Recommended brake fluid
FMVSS No. 116, fresh DOT 3 or 4 brake fluid

Maintenance and service
11-36
have the vehicle checked at your SUBARU
dealer.Never use different brands of clutch fluid to-
gether. When clutch fluid is added, be careful not to
allow any dirt into the tank.
Recommended clutch fluid
FMVSS No. 116, fresh DOT 3 or 4 brake fluidBrake booster If the brake booster does not operate as described
below, have it checked by your SUBARU dealer.
1. With the engine off, depress the brake pedal sev-
eral times, applying the same pedal force each time.
The distance the pedal travels should not vary.
2. With the brake pedal depressed, start the en-
gine. 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 about one min-
ute then turn it off. Depress the brake pedal several
times to check the brake booster. Brake booster op-
erates properly if the pedal stroke decreases with
each depression.