Today my mechanic tested the a/c on my 2011 Traverse because the a/c switch blinked a few times and went off, hence no a/c. He found that my rear a/c lines are leaking. Next week I am going to have him use a kit to seal off the rear lines. It is way cheaper than paying over $1,000 to replace the lines and I do not usually have passengers in the rear. I will also ask him why they developed a leak. On reading some other posts on this forum I see that it may be a design flaw.