Subaru Impreza 2002 Service Manual page 755

PERIODIC MAINTENANCE SERVICES
11.Cooling System
A: INSPECTION
1) Check the radiator for leakage, filling it with cool-
ant and attach the radiator cap tester to filler neck.
Then apply a pressure of 157 kPa (1.6 kg/cm
psi) and check the following points:
• Each portion of radiator for leakage
• Hose joints and other connections for leakage
NOTE:
• When attaching or detaching tester and when
operating tester, use special care not to deform ra-
diator filler neck.
Non-TURBO model
TURBO model
• When performing this check, be sure to keep the
engine stationary and fill the radiator with coolant.
• Wipe off check points before applying pressure.
• Use care not to spill coolant when detaching the
tester from radiator.
COOLING SYSTEM
2
, 23
Cap tester
GI0124
Cap tester
GI0125
PM-18
2) Check the radiator cap valve open pressure us-
ing radiator cap tester.
NOTE:
Rust or dirt on the cap may prevent the valve from
functioning normally: be sure to clean the cap be-
fore testing.
Raise the pressure until the needle of gauge stops
and see if the pressure can be retained for 5 to 6
seconds. The radiator cap is normal if a pressure
above the service limit value has been maintained
for this period.
Radiator cap valve open pressure
Standard value:
93 — 123 kPa (0.95 — 1.25 kg/cm
psi)
Service limit:
83 kPa (0.85 kg/cm
3) If the coolant temperature exceeds 76.0 to
80.0°C (169 to 176°F) while radiator is not so hot,
check thermostat. If the thermostat does not open
at 76.0 to 80.0°C (169 to 176°F), replace it with a
new one.
4) If the electric fan does not operate when coolant
temperature exceeds 90 to 94°C (194 to 201°F),
check the thermoswitch or fan motor.
2
, 14 — 18
2
, 12 psi)
GI0034
GI0035A