Sir, I have read on various forums that in most of the cases it is not always possible to drain the old coolant (be it water or old coolant) even if there is a drain bolt provided on the block as some water/coolant still remains in different parts of the cooling circuit such as pipes, heater core etc. (using blower can be helpful, as you always recommend).
So in this scenario, it is always recommended to add concentrated coolant as per half of coolant capacity (minus the reservoir bottle), of the particular car, to its empty cooling system and then top up rest of the system with distilled water, this way the system will end up with the exact required 50:50 ratio of water and coolant. Later prepare more solution of water and coolant and add to the empty reservoir bottle.
