Davis, When you rebuild the Legacy engine, or maybe before, refill the radiator and then remember to 'bleed' this type of system because the t-stat is located at the inlet side (by the lower radiator hose) and an air pocket can make this thing overheat in a minute. BEEN THERE, DONE THAT......I've got four Subaru's with this style cooling system. There is a small plastic plug near the top of the radiator on the passenger side. Remove this to get the air out of the cooling system. Gary 'The Mix'