A while ago I changed the coolant fluid and today I wanted to just check the all 3 bleed screws if there is any more air in the system.

The problem is that the plastic one on the hose to the heater broke off and now the fluid leaks. I really need the car and all the car parts store are closed, so I'm in quite the trouble. What would be the best way to fix this? How do I get this part out of the car so I can try to replace the screw?

I'll post a pic in a sec

Now that is a problem ....... But I don't think there is a quick fix? Because its the cooling system, when its at running temperature, it'll be under a lot of pressure so what ever you plug it up with would have to be able to withstand it all? ...... The only thing I can suggest is a bolt with exactly the right thread but even then I'ld be weary as you might damage the plastic thread...... Which will mean you'll need a new hose

Any breakers yards close to you? Might be worth a ring round to try and find one to get you out of trouble.

Somehow I managed to remove the broken bit and now my uncle made me a new bolt, which we tightend with teflon tape.

Should this be ok? I plan on buying the new screw anyway

Well it certainly looks like its done the job ....... The only way to tell would be to run the car up to temperature and see if any water leaks out. And if you do drive it keep an eye on the temp gauge - especially in this heat

If it does not work with the teflon try with plumber's fillasse while waiting for

Hello thank you all very much for such quick help; I did around 120km today on the highway with temperatures around 30 and the coolant didn't leak.
I'll stop at the Fiat dealership on monday and order a new bolt. To be honest I'm really pissed with the ****ty quality of parts they use as this is the second time a bolt has broken off (the first one went on the EGR) and I can honestly say that I think it was not my fault in either of the cases because the bolts were far from properly tightened...