Use engine flush with the heater on full heat (this will flush out the heater core), drain radiator, refill radiator with water, let it idle awhile again with the heater on full, shut down and let cool, remove radiator, put in new radiator, fill with coolant, fill overflow with new coolant, let it idle up to temp with the radiator cap off and the heater on full heat (leaving the cap off will assist in removing air from the system), top up as required, after 5 minutes put the cap on and Bobs your uncle.<BR><BR>Check again when cold.<BR><BR>