The level cold should be just above the core. If more than that it will push out the excess. Push out more if you are sucking air past the shaft seals on the water pump. If the water tends to come out as you decrease engine speed, like at a stop sign it is a strong indicator of air in the coolant. If it burps out coolant after stopped for a while then radiator capacity is more likely the problem. Review: quick burp when reducing engine speed = air, delayed burping = reduced radiator cooling capacity.
