Twice I have had to replace the a/c line. Each of these two times there was a leak from the lines, due to rust. In past years, you would think that a SUV this expensive would have had a corrosion issue with the metal that is being used in these parts. Each replacement cost me several thousands! Even though I get it oiled every year, I am still expecting this new line (or other components) to rust out again even after this 2nd replacement. The parts for this car are of inferior quality and have outrageous price tags! Do you know of a solution to prevent the rusting of this 2nd new line?
Hello. I would suggest that you get the A/C lines replaced again. Next time the A/C is recharged make sure they completely flush the system by adding fluid back into it, as crazy as it sounds. It’s possible to flush it with water. You can use a Shop-Vac with a suction port fitted to the AC lines to help draw out any remaining water or blow it out with compressed air.
There may still be traces of rust in the system after a new AC line was installed. The trace of rust acts as a seed to start more rust inside of the system. Unless the rest is completely removed from the system it will always have the opportunity to regrow itself. I’d suggest getting this checked by a qualified mechanic who can diagnose your A/C system and ensure everything is working as it should.