The court may require bond, or increase or decrease the amount of the bond of the personal representative when good cause therefor appears. The clerk shall inquire into the adequacy of the bond upon the filing of an inventory, appraisement or settlement or when real estate is sold, mortgaged, leased or taken possession of under order of court and, if the bond is found to be in an amount in excess of or less than that last fixed under section 473.157, the court shall enter an order requiring an additional bond or reducing the penalty of the existing bond.