Subaru 2003 Legacy User manual

FUJI HEAVY INDUSTRIES LTD. G2300GE4
2003 LEGACY SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 3
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
FUEL INJECTION (FUEL SYSTEMS) FU(H4DOSTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES) EC(H4DOSTC)
INTAKE (INDUCTION) IN(H4DOSTC)
MECHANICAL ME(H4DOSTC)
EXHAUST EX(H4DOSTC)
COOLING CO(H4DOSTC)
LUBRICATION LU(H4DOSTC)
SPEED CONTROL SYSTEMS SP(H4DOSTC)
IGNITION IG(H4DOSTC)
STARTING/CHARGING SYSTEMS SC(H4DOSTC)
ENGINE (DIAGNOSTICS) EN(H4DOSTC)

COOLING CO(H4DOSTC)
Page
1. General Description ....................................................................................2
2. Radiator Main Fan System..........................................................................7
3. Radiator Sub Fan System.........................................................................11
4. Engine Coolant..........................................................................................15
5. Water Pump..............................................................................................17
6. Thermostat................................................................................................21
7. Radiator.....................................................................................................23
8. Radiator Cap.............................................................................................27
9. Radiator Main Fan and Fan Motor............................................................28
10. Radiator Sub Fan and Fan Motor..............................................................30
11. Reservoir Tank..........................................................................................32
12. Coolant Filler Tank....................................................................................33
13. Engine Cooling System Trouble in General..............................................34

CO(H4DOSTC)-2
COOLING GENERAL DESCRIPTION
1. General Description
A: SPECIFICATIONS
Cooling system Electric fan + Forced engine coolant circulation sys-
tem
Total engine coolant capacity 2(US qt, Imp qt) MT: Approx. 7.7 (8.1, 6.8)
AT: Approx. 7.6 (8.0, 6.7)
Water pump
Type Centrifugal impeller type
Discharge performance I
Discharge 20 2(5.3 US gal, 4.4 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 760 rpm —2.9 kPa [0.3 mAq (1.0 ftAq)]
Engine coolant temperature 85°C (185°F)
Discharge performance II
Discharge 100 2(26.4 US gal, 22.0 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 3,000 rpm —49.0 kPa [5.0 mAq (16.4 ftAq)]
Engine coolant temperature 85°C (185°F)
Discharge performance III
Discharge 200 2(52.8 US gal, 44.0 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 6,000 rpm —225.4 kPa [23.0 mAq (75.5 ftAq)]
Engine coolant temperature 85°C (185°F)
Impeller diameter 76 mm (2.99 in)
Number of impeller vanes 8
Pump pulley diameter 60 mm (2.36 in)
Clearance between impel-
ler and case Standard 0.5 —0.7 mm (0.020 —0.028 in)
Limit 1.0 mm (0.039 in)
“Thrust”runout of impeller end 0.5 mm (0.020 in)
Thermostat
Type Wax pellet type
Starts to open 76 —80°C (169 —176°F)
Fully opened 91°C (196°F)
Valve lift 9.0 mm (0.354 in) or more
Valve bore 35 mm (1.38 in)
Radiator fan Motor 75 W (main fan)
75 W (sub fan)
Fan diameter ×Blade 300 mm (11.81 in) ×5 (main fan)
300 mm (11.81 in) ×4 (sub fan)
Radiator
Type Down flow, pressure type
Core dimensions 691.5 ×340 ×16 mm
(27.22 ×13.39 ×0.63 in)
Pressure range in which cap valve is open or closed
Above: 108±15 kPa
(1.1±0.15 kg/cm2, 16±2 psi)
Below: −1.0 to −4.9 kPa
(−0.01 to −0.05 kg/cm2, −0.1 to −0.7 psi)
Fins Corrugated fin type
Reservoir
tank Capacity 0.5 2(0.5 US qt, 0.4 Imp qt)

CO(H4DOSTC)-3
COOLING
GENERAL DESCRIPTION
B: COMPONENT
1. WATER PUMP
(1) Thermostat case (5) Gasket Tightening torque: N·m (kgf-m, ft-lb)
(2) Gasket (6) Heater by-pass hose T1: First 12 (1.2, 8.7)
Second 12 (1.2, 8.7)
(3) Thermostat (7) Coolant filler tank by-pass hose
(4) Water pump ASSY (8) Water by-pass hose T2: 6.5 (0.66, 4.8)
( 1 )
( 2 )
( 3 )
( 4 )
( 5 )
( 6 ) ( 7 )
T2
( 8 )
T2
T2
T1
T1
CO-00201

CO(H4DOSTC)-4
COOLING GENERAL DESCRIPTION
2. RADIATOR AND RADIATOR FAN
(1) Radiator lower cushion (14) Radiator main fan and main fan
motor ASSY (25) ATF outlet hose B (AT vehicles only)
(2) Radiator
(3) Radiator upper cushion (15) Radiator outlet hose (26) ATF inlet hose B (AT vehicles
only)
(4) Radiator upper bracket (16) Radiator drain plug
(5) Clamp (17) Engine coolant filler tank (27) ATF pipe (AT vehicles only)
(6) Radiator inlet hose (18) Engine coolant filler tank cap
(7) Engine coolant reservoir tank cap (19) Engine coolant hose Tightening torque: N·m (kgf-m, ft-lb)
(8) Overflow hose (20) Radiator lower bracket T1: 3.4 (0.35, 2.5)
(9) Engine coolant reservoir tank (21) O-ring T2: 4.4 (0.45, 3.3)
(10) Overflow pipe (22) ATF hose clamp (AT vehicles
only) T3: 4.9 (0.50, 3.6)
(11) Sub fan shroud T4: 18 (1.8, 13.0)
(12) Radiator sub fan and sub fan
motor ASSY (23) ATF outlet hose A (AT vehicles only) T5: 12 (1.2, 8.7)
(13) Main fan shroud (24) ATF inlet hose A (AT vehicles
only)
CO-00145
T3 (7)
(18)
(17)
(5)
(5) (19)
(9)
T3
T3
T5
T2
T2
T1
(13)
(11)
(14)
(5)
(5)
(6)
(8)
T4
(5)
(15)
(1)
(2)
(20)
(16)
(3)
(4)
(10 )
(21)
(12)
T1
(24)
(25)
(22)
(22)
(22)
(22)
(22)
(22)
T5
(26)
(27)
(23)

CO(H4DOSTC)-5
COOLING
GENERAL DESCRIPTION
C: CAUTION
•Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust or dirt.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly, and replacement.
•Be careful not to burn your hands, because each
part in the vehicle is hot after running.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Placeshopjacksorsafetystandsatthespecified
points.
•Before disconnecting electrical connectors of
sensors or units, be sure to disconnect ground ca-
ble from battery.

CO(H4DOSTC)-6
COOLING GENERAL DESCRIPTION
D: PREPARATION TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
499977100 (MT
model) CRANK PULLEY WRENCH Used for fixing crankshaft pulley when loos- ening and tightening crankshaft pulley bolts.
499977400 (AT
model) CRANK PULLEY WRENCH Used for fixing crankshaft pulley when loos- ening and tightening crankshaft pulley bolts.
18231AA010 CAMSHAFT
SPROCKET
WRENCH
•Used for removing and installing camshaft
sprocket. (Intake side)
•Camshaft sprocket wrench (499207100) is
also available.
499207400 CAMSHAFT
SPROCKET
WRENCH
Used for removing and installing camshaft
sprocket. (Exhaust side)
ST-499977100
ST-499977400
ST18231AA010
ST-499207400

CO(H4DOSTC)-7
COOLING
RADIATOR MAIN FAN SYSTEM
2. Radiator Main Fan System
A: SCHEMATIC
CO-00146
2 1 4 3
21 22 24 20
8
7
5 9
20A
20A
SUB FAN
RELAY
AIR CONDITIONING RELAY HOLDER
SUB FAN
MOTOR
MAIN FAN
MOTOR
MAIN FAN
RELAY
F28
F16
F66 F27
1 2
F17
B100 F2
B72
1 2
8
9
NO. 3
NO. 18
NO. 17
SBF-4
SBF-1
IGNITION
SWITCH
B72
34
12
B137
BATTERY
17 28
B137
ECM
F16 F17
2 1
F27
1 2
3 4
5 6 7
8
9
11
10
13
12 14 21
20
23
22 24 31
30
33
32 34
1615 17
18
19
2625 27
28
29
35
36
F66 F28
F2
12 3 4 5 6 7
9 10 11 12 13 14 15 16
8127895634
101112192021 293031 1314151617 2728 18 2223242526

CO(H4DOSTC)-8
COOLING RADIATOR MAIN FAN SYSTEM
B: INSPECTION
DETECTING CONDITION:
Condition:
•Engine coolant temperature is above 95°C (203°F).
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
•Radiator main fan does not rotate under the above conditions.
Step Value Yes No
1 CHECK POWER SUPPLY TO MAIN FAN MO-
TOR.
CAUTION:
Be careful not to overheat engine during re-
pair.
1) Turn ignition switch to OFF.
2) Disconnect connector from main fan motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
95°C (203°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure voltage between main fan motor
connector and chassis ground.
Connector & terminal
(F17) No. 2 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 2. Go to step 5.
2 CHECK GROUND CIRCUIT OF MAIN FAN
MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied valve?
5 ΩGo to step 3. Repairopencircuit
in harness
between main fan
motor connector
and chassis
ground.
3 CHECK POOR CONTACT.
Check poor contact in main fan motor connec-
tor.
Is there poor contact in main fan motor con-
nector?
There is poor contact. Repair poor con-
tact in main fan
motor connector.
Go to step 4.
4 CHECK MAIN FAN MOTOR.
Connect battery positive (+) terminal to termi-
nal No. 2, and negative (−) terminal to terminal
No. 1 of main fan motor connector.
Does the main fan rotate?
The main fan rotates. Repair poor con-
tact in main fan
motor connector.
Replace main fan
motor with a new
one.
5 CHECK POWER SUPPLY TO MAIN FAN RE-
LAY.
1) Turn ignition switch to OFF.
2) Remove main fan relay from A/C relay
holder.
3) Measure voltage between main fan relay
terminal and chassis ground.
Connector & terminal
(F66) No. 8 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 6. Go to step 7.

CO(H4DOSTC)-9
COOLING
RADIATOR MAIN FAN SYSTEM
6 CHECK POWER SUPPLY TO MAIN FAN RE-
LAY.
1) Turn ignition switch to ON.
2) Measure voltage between main fan relay
terminal and chassis ground.
Connector & terminal
(F66) No. 5 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 10. Go to step 9.
7 CHECK 20 A FUSE.
1) Remove 20 A fuse from A/C relay holder.
2) Check condition of fuse.
Is the fuse blown-out?
Fuse is blown-out. Replace fuse. Go to step 8.
8 CHECK POWER SUPPLY TO A/C RELAY
HOLDER 20 A FUSE TERMINAL.
Measure voltage of harness between A/C relay
holder 20 A fuse terminal and chassis ground.
Connector & terminal
(F27) No. 1 (+) — Chassis ground (
−
−−
−
):
Does the measured valueexceed the specified
value?
10 V Repairopencircuit
in harness
between20 A fuse
and main fan relay
terminal.
Repairopencircuit
in harness
betweenmainfuse
box connector and
20 A fuse terminal.
9 CHECK FUSE.
1) Turn ignition switch to OFF.
2) Remove fuse No. 18 from joint box.
3) Check fuse.
Is the fuse blown-out?
Fuse is blown-out. Replace fuse. Repairopencircuit
in harness
between main fan
relay and ignition
switch.
10 CHECK MAIN FAN RELAY.
1) Turn ignition switch to OFF.
2) Measure resistance of main fan relay.
Terminal
No. 8 — No. 9:
Does the measured value exceed the spec-
ified value?
1 MΩGo to step 11. Replace main fan
relay.
11 CHECK MAIN FAN RELAY.
1) Connect battery to terminals No. 5 and No.
7 of main fan relay.
2) Measure resistance of main fan relay.
Terminal
No. 8 — No. 9:
Is the measured value less than the speci-
fied valve?
1 ΩGo to step 12. Replace main fan
relay.
12 CHECK HARNESS BETWEEN MAIN FAN
RELAY TERMINAL AND MAIN FAN MOTOR
CONNECTOR.
Measure resistance of harness between main
fan motor connector and main fan relay termi-
nal.
Connector & terminal
(F17) No. 2 — (F66) No. 9:
Is the measured value less than the specified
valve?
1 ΩGo to step 13. Repairopencircuit
in harness
between main fan
motor connector
and main fan relay
terminal.
Step Value Yes No

CO(H4DOSTC)-10
COOLING RADIATOR MAIN FAN SYSTEM
NOTE:
Inspection by distributor service is required, because probable cause is deterioration of multiple parts.
13 CHECK HARNESS BETWEEN MAIN FAN
RELAY AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
main fan relay connector and ECM connec-
tor.
Connector & terminal
(F66) No. 7 — (B134) No. 14:
Is the measured value less than the speci-
fied valve?
1 ΩGo to step 14. Repairopencircuit
in harness
between main fan
relay and ECM.
14 CHECK POOR CONTACT.
Check poor contact in connector between main
fan and ECM.
Is there poor contact in connector between
main fan motor and ECM?
There is poor contact. Repair poor con-
tact connector. Contact with dis- tributor service.
Step Value Yes No

CO(H4DOSTC)-11
COOLING
RADIATOR SUB FAN SYSTEM
3. Radiator Sub Fan System
A: SCHEMATIC
CO-00146
2 1 4 3
21 22 24 20
8
7
5 9
20A
20A
SUB FAN
RELAY
AIR CONDITIONING RELAY HOLDER
SUB FAN
MOTOR
MAIN FAN
MOTOR
MAIN FAN
RELAY
F28
F16
F66 F27
1 2
F17
B100 F2
B72
1 2
8
9
NO. 3
NO. 18
NO. 17
SBF-4
SBF-1
IGNITION
SWITCH
B72
34
12
B137
BATTERY
17 28
B137
ECM
F16 F17
2 1
F27
1 2
3 4
5 6 7
8
9
11
10
13
12 14 21
20
23
22 24 31
30
33
32 34
1615 17
18
19
2625 27
28
29
35
36
F66 F28
F2
12 3 4 5 6 7
9 10 11 12 13 14 15 16
8127895634
101112192021 293031 1314151617 2728 18 2223242526

CO(H4DOSTC)-12
COOLING RADIATOR SUB FAN SYSTEM
B: INSPECTION
NOTE:
Radiator sub fan system is for model with A/C.
DETECTING CONDITION:
Condition (1):
•Engine coolant temperature is below 95°C (203°F).
•A/C switch is turned ON.
•Vehicle speed is below 19 km/h (12 MPH).
Condition (2):
•Engine coolant temperature is above 100°C (212°F).
•A/C switch is turned OFF.
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
•Radiator sub fan does not rotate under conditions (1) and (2) above.
Step Value Yes No
1 CHECK POWER SUPPLY TO SUB FAN MO-
TOR.
C
AUTI
O
N:
Be careful not to overheat engine during re-
pair.
1) Turn ignition switch to OFF.
2) Disconnect connector from sub fan motor
and main fan motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
100°C (212°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure voltage between sub fan motor
connector and chassis ground.
Connector & terminal
(F16) No. 2 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 2. Go to step 5.
2 CHECK GROUND CIRCUIT OF SUB FAN
MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between sub fan motor
connector and chassis ground.
Connector & terminal
(F16) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied valve?
5 ΩGo to step 3. Repairopencircuit
in harness
between sub fan
motor connector
and chassis
ground.
3 CHECK POOR CONTACT.
Check poor contact in sub fan motor connec-
tor.
Is there poor contact in sub fan motor connec-
tor?
Repair poor con-
tact in sub fan
motor connector.
Go to step 4.
4 CHECK SUB FAN MOTOR.
Connect battery positive (+) terminal to termi-
nal No. 2, and negative (−) terminal to terminal
No. 1 of sub fan motor connector.
Does the sub fan rotate?
Sub fan rotates. Repair poor con-
tact in sub fan
motor connector.
Replace sub fan
motor with a new
one.

CO(H4DOSTC)-13
COOLING
RADIATOR SUB FAN SYSTEM
5 CHECK POWER SUPPLY TO SUB FAN RE-
LAY.
1) Turn ignition switch to OFF.
2) Remove sub fan relay from A/C relay
holder.
3) Measure voltage between sub fan relay ter-
minal and chassis ground.
Connector & terminal
(F28) No. 21 (+) — Chassis ground ( −
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 6. Go to step 7.
6 CHECK POWER SUPPLY TO SUB FAN RE-
LAY.
1) Turn ignition switch to ON.
2) Measure voltage between sub fan relay ter-
minal and chassis ground.
Connector & terminal
(F28) No. 24 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 10. Go to step 9.
7 CHECK 20 A FUSE.
1) Remove 20 A fuse from A/C relay holder.
2) Check condition of fuse.
Is the fuse blown-out?
Fuse is blown-out. Replace fuse. Go to step 8.
8 CHECK POWER SUPPLY TO A/C RELAY
HOLDER 20 A FUSE TERMINAL.
Measure voltage of harness between A/C relay
holder 20 A fuse terminal and chassis ground.
Connector & terminal
(F27) No. 3 (+) — Chassis ground ( −
−−
−
):
Does the measured valueexceed the specified
value?
10 V Repairopencircuit
in harness
between20 A fuse
and sub fan relay
terminal.
Repairopencircuit
in harness
betweenmainfuse
box connector and
20 A fuse terminal.
9 CHECK FUSE.
1) Turn ignition switch to OFF.
2) Remove fuse No. 17 from joint box.
3) Check condition of fuse.
Is the fuse blown-out?
Fuse is blown-out. Replace fuse. Repairopencircuit
in harness
between sub fan
relay and ignition
switch.
10 CHECK SUB FAN RELAY.
1) Turn ignition switch to OFF.
2) Measure resistance of sub fan relay.
Terminal
No. 20 — No. 21:
Does the measured value exceed the spec-
ified value?
1 MΩGo to step 11. Replace sub fan
relay.
11 CHECK SUB FAN RELAY.
1) Connect battery to terminals No. 22 and
No. 24 of sub fan relay.
2) Measure resistance of sub fan relay.
Terminal
No. 20 — No. 21:
Is the measured value less than the speci-
fied valve?
1 ΩGo to step 12. Replace sub fan
relay.
Step Value Yes No

CO(H4DOSTC)-14
COOLING RADIATOR SUB FAN SYSTEM
NOTE:
Inspection by distributor service is required, because probable cause is deterioration of multiple parts.
12 CHECK HARNESS BETWEEN SUB FAN RE-
LAY TERMINAL AND SUB FAN MOTOR
CONNECTOR.
Measure resistance of harness between sub
fan motor connector and sub fan relay termi-
nal.
Connector & terminal
(F16) No. 2 — (F28) No. 20:
Is the measured value less than the specified
valve?
1 ΩGo to step 13. Repairopencircuit
in harness
between sub fan
motor and sub fan
relay connector.
13 CHECK HARNESS BETWEEN SUB FAN RE-
LAY AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
sub fan relay connector and ECM connec-
tor.
Connector & terminal
(F28) No. 22 — (B134) No. 13:
Is the measured value less than the speci-
fied valve?
1 ΩGo to step 14. Repairopencircuit
in harness
between sub fan
relay and ECM.
14 CHECK POOR CONTACT.
Check poor contact in connector between sub
fan and ECM.
Is there poor contact in connector between sub
fan motor and ECM?
There is poor contact. Repair poor con-
tact connector. Contact with dis- tributor service.
Step Value Yes No

CO(H4DOSTC)-15
COOLING
ENGINE COOLANT
4. Engine Coolant
A: REPLACEMENT
1. DRAINING LOF ENGINE COOLANT
1) Lift-up the vehicle.
2) Remove under cover.
3) Remove drain cock to drain engine coolant into
container.
NOTE:
Remove radiator cap so that engine coolant will
drain faster.
2. FILLING OF ENGINE COOLANT
1) Fill engine coolant into radiator up to filler neck
position.
Engine coolant amount for refill:
MT model;
Approx. 7.7 2(8.1 US qt, 6.8 Imp qt)
AT model;
Approx. 7.6 2(8.0 US qt, 6.7 Imp qt)
CAUTION:
The SUBARU Genuine Coolant containing anti-
freeze and anti-rust agents is especially made
for SUBARU engine, which has an aluminum
crankcase. Always use SUBARU Genuine Cool-
ant, since other coolant may cause corrosion.
2) Fill engine coolant into reservoirtank up to upper
level.
3) Attach radiator cap and reservoir tank cap prop-
erly.
4) Warm-up engine completely for more than five
minutes at 2,000 to 3,000 rpm.
5) If engine coolant level drops in radiator, add en-
gine coolant to filler neck position.
6) If engine coolant level drops from upper level of
reservoir tank, add engine coolant to upper level.
7) Attach radiator cap and reservoir tank cap prop-
erly.
B: INSPECTION
1. RELATIONSHIP LOF SUBARU COOL-
ANT CONCENTRATION AND FREEZING
TEMPERATURE
The concentration and safe operating temperature
of the SUBARU coolant is shown in the diagram.
Measuring the temperature and specific gravity of
the coolant will provide this information.
[Example]
If the coolant temperature is 25°C (77°F) and its
specific gravity is 1.054, the concentration is 35%
(point A), the safe operating temperature is −14°C
(7°F) (point B), and the freezing temperature is −
20°C (−4°F) (point C).
CO-00083
CO-00010
FULL
LOW
Full level
Low level
CO-00062
1.000
1.010
–40
(–40)
1.020
1.030
1.040
1.050
1.060 (1.054)
1.070 CB
A
1.080
1.090
1.100
–30
(–22)
–20
(–4) –10 (14) 0 (32) 10 10%
20%
30%
40%
50%
60%
(50) 20
25˚C
(77˚F)
(68) 30
(86) 40 (104) 50 (122)
Specific gravity of coolant
Safe operating temperature
Concentration
of coolant
Freezing
temperature
Coolant temperature ˚C (˚F)

CO(H4DOSTC)-16
COOLING ENGINE COOLANT
2. PROCEDURE LTO ADJUST THE CON-
CENTRATION OF THE COOLANT
To adjust the concentration of the coolant accord-
ing to temperature, find the proper fluid concentra-
tion in the above diagram and replace the
necessary amount of coolant with an undiluted so-
lution of SUBARU genuine coolant (concentration
50).
The amount of coolant that should be replaced can
be determined using the diagram.
[Example]
Assume that the coolant concentration must be in-
creased from 25% to 40%. Find point A, where the
25% line of coolant concentration intersects with
the 40% curve of the necessary coolant concentra-
tion, and read the scale on the vertical axis of the
graph at height A. The quantity of coolant to be
drained is 2.1 liters (2.2 US qt, 1.8 Imp qt). Drain
2.1 liters (2.2 US qt, 1.8 Imp qt) of coolant from the
cooling system and add 2.1 liters (2.2 US qt, 1.8
Imp qt) of the undiluted solution of SUBARU cool-
ant.
If a coolant concentration of 50% is needed, drain
all the coolant and refill with the undiluted solution
only.
CO-00063
10
0
1
(1.1,
0.9)
(2.1,
1.8)
(3.2,
2.6)
2
45%
40%
35%
30%
25%
20%
15%
10% 20 30 40 50
3
A
Quantity of coolant to be drained (US qt, lmp qt)
Necessary concentration
of coolant
Concentration of coolant in
the vehicle cooling system %
Concentration of coolant in vehicle
and quantity to be drained

CO(H4DOSTC)-17
COOLING
WATER PUMP
5. Water Pump
A: REMOVAL
1) Disconnect ground cable from battery.
2) Lift-up the vehicle.
3) Remove under cover.
4) Drain engine coolant completely.
<Ref. to CO(H4DOSTC)-15, DRAINING LOF EN-
GINE COOLANT, REPLACEMENT, Engine Cool-
ant.>
5) Remove radiator under cover.
6) Disconnect connectors from radiator main fan
(A) and sub fan (B) motors.
7) Remove bolt and clamps, and then remove wa-
ter by-pass pipe. (MT model)
8) Disconnect radiator outlet hose (A) and heater
hose (B) from water pump.
9) Disconnect water by-pass hose (C) and oil cool-
er hose (D).
10) Lower the vehicle.
11) Remove air intake duct.
12) Disconnect overflow hose.
13) Remove reservoir tank.
14) Remove radiator main fan and sub fan assem-
blies. <Ref. to CO(H4DOSTC)-28, REMOVAL, Ra-
diator Main Fan and Fan Motor.> and <Ref. to
CO(H4DOSTC)-30, REMOVAL, Radiator Sub Fan
and Fan Motor.>
FU-00009
( A ) ( B )
CO-00084
CO-00147
( A ) ( B )
( C )
( D )
CO-00148
IN-00059
CO-00086
CO-00087

CO(H4DOSTC)-18
COOLING WATER PUMP
15) Remove V-belts.
<Ref. to ME(H4DOSTC)-42, REMOVAL, V-belt.>
16) Remove timing belt.
<Ref. to ME(H4DOSTC)-47, REMOVAL, Timing
Belt Assembly.>
17) Remove automatic belt tension adjuster.
18) Remove belt idler (B).
19) Remove belt idler No. 2 (C).
20) Remove camshaft position sensor. <Ref. to
FU(H4DOSTC)-30, REMOVAL, Camshaft Position
Sensor.>
21) Remove left-hand camshaft sprocket by using
ST.
ST 18231AA010 CAMSHAFT SPROCKET
WRENCH (Intake side)
ST 499207400 CAMSHAFT SPROCKET
WRENCH (Exhaust side)
22) Remove tensioner bracket.
23) Remove left-hand belt cover No. 2.
24) Remove water pump.
B: INSTALLATION
1) Install water pump onto left-hand cylinder block.
NOTE:
•Replace gasket with a new one.
•When installing water pump, tighten bolts in two
stages in alphabetical sequence as shown in fig-
ure.
Tightening torque:
First:
12 N·m (1.2 kgf-m, 8.7 ft-lb)
Second:
12 N·m (1.2 kgf-m, 8.7 ft-lb)
( A )
( B )
( C )
CO-00149
CO-00150
ST
CO-00020
CO-00151
CO-00021
( A )
( B )
( C )
( D )
( E )
( F )
CO-00152