(a) An action may be commenced against an executor or administrator at any time after the expiration of twelve months from the granting of letters testamentary or of administration and until the final settlement of the estate and discharge of such executor or administrator from the trust, and not otherwise.
(b) An action against an executor or administrator shall not be commenced until the claim of the plaintiff has been duly presented to such executor or administrator and by him disallowed. If such claim is presented after the expiration of the period of six months mentioned in sections 391 and 392 of this title, the executor or administrator in an action therefor shall only be liable to the extent of the assets in his hands at the time the summons is served upon him.