Is near impossible with appropriate precautions and tools to proper recover plastics like that. The epoxy or glue alone aren’t enough because they can’t stick to that kind of plastics.

The only two options really available:

1. Tapping the radiator side and insert a nipple with a bit of Teflon (like someone already said, that’s the easier way);

2. Find a copper/aluminum tube with the exact outer diameter of the inner diameter of the broken part and get it stiff inside like to reinforcing it.

Only then you can get some steel Epoxy to bond all together or try to slowly melt both sides together with an old soldering iron (melting the plastic from both sides), but is really really difficult to do it properly.

P.S. Remember to use some kind of mask to protect lungs and eyes from fumes if you are melting that plastics.

The responses it gives to every input from the user. Just like when you just press a bit the throttle and you feel that the engine is ready for you. Or like when you get fast corners and you feel all one with the car…