When it is dry no sounds, when it rains or the lib get wet the squeak to a grinding starts, and it will go on for days. I took my KJ to the dealer and they say it is the brakes, but when I depress the brakes the grinding won't go away.

Any insight would be very much appreciated

I don't know much about brakes, but a neighbor of mine had the sounds you are describing with his XJ. Replaced the brakes and now everything is back to normal. The dealer may just be on to something.