Tip for removing radiator
unfortunately if you dont use compressed air and water in reverse flow you are not knocking all the buildup off and not the best way to do it. I used to own a Rad shop and that is the only way to do it properly. Remember to remove the top hose and take an old upper hose and cut it down to a 90 to use to flush.
I also recommend after you flush it with compressed air and water, to add in 7 liters of antifreeze, one per cylinder and one in the overflow then top up with water. Run to temp with the heater on and get you will usually get all the air out of the system that way.