Subaru 1998 Forester Owner's Manual page 246

5. Remove the air vent plug from the radiator.
Fill up to here
6. Slowly pour the coolant and fill to the radiator filler neck and to the
reserve tank's "FULL" level mark. Do not pour the coolant too quickly, as
this may lead to insufficient air bleeding and trapped air in the system.
Coolant capacity
6.6 US qt (6.2 liters, 5.5 Imp qt)
7. Put the air vent plug back on and tighten firmly.
Rubber gaskets
8. Put the radiator cap back on and tighten firmly. At this time, make
sure that the rubber gasket in the radiator cap is correctly in place.
9. Start and run the engine for more than five minutes at 2,000 to 3,000
rpm.
10-16
Filler neck
HS0182
HG0115
"FULL"
level mark
"LOW"
level mark
HS0178