Subaru Legacy IV (2008 year). Manual - part 496

CO(H6DO)-10

Engine Coolant

COOLING

3. Engine Coolant

A: REPLACEMENT

1. DRAINING OF ENGINE COOLANT

1) Set the vehicle on a lift.
2) Lift up the vehicle.
3) Remove the under cover.
4) Remove the drain plug to drain engine coolant
into container.

NOTE:
Remove the radiator cap so that engine coolant will
drain faster.

5) Install the drain plug.
6) Install the under cover.

2. FILLING OF ENGINE COOLANT

1) Pour cooling system conditioner through the fill-
er neck.

Cooling system protective agent:

Refer to “SPECIFICATION” for the cooling 
system protective agent. <Ref. to CO(H6DO)-
2, SPECIFICATION, General Description.>

2) Pour engine coolant into the radiator up to the
filler neck position.

Recommended engine coolant:

Refer to “SPECIFICATION” for the recom-
mended engine coolant. <Ref. to CO(H6DO)-
2, SPECIFICATION, General Description.>

Amount of engine coolant:

Refer to “SPECIFICATION” for the amount of 
engine coolant. <Ref. to CO(H6DO)-2, SPECI-
FICATION, General Description.>

Engine coolant concentration:

Refer to “ADJUSTMENT” for the engine cool-
ant concentration. <Ref. to CO(H6DO)-11, 
ADJUSTMENT, Engine Coolant.>

NOTE:
The SUBARU Super Coolant containing anti-
freeze and anti-rust agents is especially made for
SUBARU engine, which has an aluminum cylinder
block. Always use SUBARU Super Coolant since
other coolants may cause corrosion.

3) Fill engine coolant into the reservoir tank up to
“FULL” level.

4) Close the radiator cap and start the engine.
Race 5 to 6 times at 3,000 rpm or less, then stop
the engine. (Complete this operation within 40 sec-
onds.)
5) Wait for one minute after the engine stops, and
open the radiator cap. If the engine coolant level
drops, add engine coolant into radiator up to the fill-
er neck position.
6) Perform the procedures 4) and 5) again.
7) Attach the radiator cap and reservoir tank cap
properly.
8) Start the engine and operate the heater at max-
imum hot position and the blower speed setting to
“LO”.
9) Run the engine at 2,000 rpm or less until radiator
fan starts and stops.

NOTE:
Be careful with the engine coolant temperature
gauge to prevent overheating.
10) Stop the engine and wait until the engine cool-
ant temperature lowers to 30°C (86°F) or less.
11) Open the radiator cap. If the engine coolant lev-
el drops, add engine coolant into radiator up to the
filler neck position and reservoir tank to the “FULL”
level.
12) Attach the radiator cap and reservoir tank cap
properly.
13) Set the heater setting to maximum hot position
and the blower speed setting to “LO” and start the
engine. Perform racing at 3,000 rpm or less. If the
flowing sound is heard from heater core, repeat the
procedures from step 9).

CO-02012

(1) FULL

(2) LOW

(1)

(2)

CO-00110

CO(H6DO)-11

Engine Coolant

COOLING

B: ADJUSTMENT

1. PROCEDURE TO ADJUST THE SUBARU SUPER COOLANT CONCENTRATION

CAUTION:
Use the SUBARU Super Coolant with a 50 — 60% concentration in order to obtain maximum anti-
freeze and anti-rust performance.
To adjust the concentration of SUBARU Super Coolant according to temperature, find the proper SUBARU
Super Coolant concentration in the table, and add diluting water to the SUBARU Super Coolant (concentrat-
ed type) until it reaches the proper dilution.

Engine coolant and diluting water:

Refer to “SPECIFICATION” for the recommended engine coolant and diluting water. <Ref. to 
CO(H6DO)-2, SPECIFICATION, General Description.>

Relationship of Subaru Super Coolant concentration and freezing temperature

SUBARU Super Coolant concentration

50%

55%

60%

Freezing temperature

–36°C (–33°F)

–41°C (–42°F)

–50°C (–58°F)

CO(H6DO)-12

Water Pump

COOLING

4. Water Pump

A: REMOVAL

1) Remove the radiator. <Ref. to CO(H6DO)-15,
REMOVAL, Radiator.>
2) Remove the V-belts. <Ref. to ME(H6DO)-42,
REMOVAL, V-belt.>
3) Remove the crank pulley. <Ref. to ME(H6DO)-
43, REMOVAL, Crank Pulley.>
4) Remove the front chain cover. <Ref. to
ME(H6DO)-44, REMOVAL, Front Chain Cover.>
5) Remove the timing chain assembly. <Ref. to
ME(H6DO)-46, REMOVAL, Timing Chain Assem-
bly.>
6) Remove the water pump.

NOTE:
When the water pump cannot be removed easily,
screw-in the bolt (A) to the threaded end to remove
water pump.

B: INSTALLATION

1) Install the water pump to rear chain cover.

NOTE:
• Use new O-rings.
• Apply engine coolant to O-ring.

Tightening torque

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

2) Install the timing chain assembly. <Ref. to
ME(H6DO)-47, INSTALLATION, Timing Chain As-
sembly.>
3) Install the front chain cover. <Ref. to ME(H6DO)-
44, INSTALLATION, Front Chain Cover.>
4) Install the crank pulley. <Ref. to ME(H6DO)-43,
INSTALLATION, Crank Pulley.>
5) Install the V-belts. <Ref. to ME(H6DO)-42, IN-
STALLATION, V-belt.>
6) Install the radiator. <Ref. to CO(H6DO)-16, IN-
STALLATION, Radiator.>
7) Fill engine coolant. <Ref. to CO(H6DO)-10,
FILLING OF ENGINE COOLANT, REPLACE-
MENT, Engine Coolant.>

C: INSPECTION

1) Check the water pump bearing for smooth rota-
tion.
2) Check the water pump sprocket for abnormali-
ties.

CO-02013

(A)

(A)

CO-02014

CO(H6DO)-13

Thermostat

COOLING

5. Thermostat

A: REMOVAL

1) Set the vehicle on a lift.
2) Lift up the vehicle.
3) Remove the under cover.
4) Drain engine coolant completely. <Ref. to
CO(H6DO)-10, DRAINING OF ENGINE COOL-
ANT, REPLACEMENT, Engine Coolant.>
5) Disconnect the radiator outlet hose from thermo-
stat cover.

6) Remove the thermostat cover, and then remove
the thermostat.

B: INSTALLATION

1) Install a gasket to thermostat.

NOTE:
Use a new gasket.
2) Install the thermostat and thermostat cover.

NOTE:
The jiggle pin must face upward when installing.

Tightening torque:

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

3) Connect the radiator outlet hose to thermostat
cover.
4) Install the under cover.
5) Lower the vehicle.
6) Fill engine coolant. <Ref. to CO(H6DO)-10,
FILLING OF ENGINE COOLANT, REPLACE-
MENT, Engine Coolant.>

(A) Thermostat cover

(B) Thermostat

CO-02015

CO-02164

(A)

(B)

(A) Thermostat cover

(B) Thermostat

(C) Gasket

(D) Jiggle pin

CO-02165

(D)

(A)

T

(B)

(C)