Feel into the intercooler just in case the O-ring is inside, only use Viton O-rings to replace the old ones, in your case to repair as you have none, i did a mod i these intercooler bends sometime back now, so three rings could be used or just two with out the one on the end.
1
Always make sure the bend is fully pushed home into the intercooler.
2
I may also fit this intercooler hose mod to my car, i had one on my other tourer years ago it is an alloy one from a BMW.
3