A short review on flushing.I do not use a flushing T why cut into a perfectly good hose and create another place to leak.Using a piece heater hose and the male end of a garden hose repair kit make a fitting to attach the hose to the water pump inlet. Flush out the system pinch off the vehicles hose (while it is flushing) so it runs through the entire system. Remove the garden hose fitting and attach it to the heater hose and flush again block off the pump outlet while flushing so it backflushes the entire system.Run some water through the radiator. drain and refill be sure the heater blows hot air then you should not have an air lock. If you have a vacuum controlled heater valve use an external vacuum source to open the valve or run the vehicle(with the heater on hot) This is messy. I only use regular antifreeze and chemical flush only in extreme circumstances. I do use a slight amount of water pump lube about half the bottle. One more hint pinch off the water supply to create a pulse effect this seems to help break gunk loose mainly when backflushing.