I had that two tubes issue on a Carrier Air V.. Cost me 1,000 (rounded) to replace it when they rubbed holes in each other.. I am not pleased with Carrier.
On the mate to it which does not run as often I made an edit like the above poster so it won't happen.
On a neighbor's Carrier Air V (By the way they are no longer made) he had a "Rattle" on his A/C and trust me you NEED A/C here in the summer.. We investigated and quickly narrowed it down to the blower cage. It had cracks extending into the hub.. Of course it's late Friday. No way are you going to find a replacement at that hour..... Unless you looked in my basement of course (I salvaged everythign I could off the one with the hole in the plumbing,, including the very part he needed) odds of that happening.. Let's just say he needed to make a decision.
Buy lotto tickets while you are hot
Do not buy lotto tickets cause you already used up your alotment of luck today.