The smaller diameter is the high pressure side but either way you can't just patch the hole; that whole section of line needs to be replaced. Just be careful that the system is completely discharged before disconnecting anything. Also, fines are quite hefty for releasing refrigerant into the atmosphere not to mention it messes up our earth, just an FYI.

 

sory to hear your car was stolen.. wish someone would steal mine. anyway I took my car to the dealership to get the a/c fixed. found the problem was it was low on R-134 and there was a bad sensor in the condensor ($40) part. all in all cost me $238. Works great now