Nudged something on aircon system, hissing noise?

[robbocop33]

This was odd, i was putting new mounting rubbers on the bottom of the radiator on my Megane, had to drop subframe mounting bracket that holds radiator base. While i was bolting up the subframe i was tightening up the two bolts that hold it on at the front and i heard a hissing? I thought i had maybe accidentally lay on a tin of wd40, one of my favourite tricks, but i noticed it must be the aircon! .
I couldn't exactly see where it was coming from and was surprised looking at how substantial aircon hoses look that it would leak so easily getting nudged??
Is there any part of the system that is particularly flimsy or something like a valve or something that would release pressure easily?
It sounded low down,i wasn't really near anything when putting the suframe on to be honest, pipes were pretty clear of me.

[GreenV8S]

Hopefully it has some dye in it so you can see where the leak was.

[M_A_S]

The most common place for air con gas leaks is the radiator, normally due to corrosion. I suspect disturbing the mountings has slightly accelerated the process.