I am replacing a galvanized pipe which has rusted out badly. This pipe connects to another galvanized pipe in the wall which seems to be a vent pipe as well. Where the rusted pipe sat has destroyed the threads in a 3/4" spot, thus causing my new PVC fitting to leak as well. I used plumber's tape to get a good seal but apparently it didn't do the job. What else can I do short of removing a good chunk of my kitchen cabinets and wall the replace this T fitting in the wall?
It is pretty common for the nipple threads to rust off, but usually the wall elbow is OK. Try multiple wraps of teflon tape and pipe dope, that may work. But I suspect you will need to replace the elbow. And no, it is not a simple job.