Possible issue with rear brakes

07 5.7L 2wd 280k+

I'm starting to notice an issue with the rear passenger side brake caliper, Right Rear Caliper. I've replaced this caliper already, but it wasn't because it was frozen or anything, but it was starting to stick. I replaced it due to a brake rotor failure and completely destroyed the drum inside, so I replaced it with an Autozone one, since at the time I was struggling financially and living in the Bay area didn't help. This caliper is starting to stick as well, I've been cleaning and lubing the guide pins on it every time I rotate tires, but it's still sticking. Anyone else have this same issue?? It doesn't bother me lubing and keeping an eye on this specific side, but it's the only side with the issue. Starting to wonder if the heat from the exhaust is starting to get to it, or overheating the lube inside the rotor. When I purged the brake fluid this weekend it came out pretty dark. Only side that was dark as well.

 

You need to look at the right rear hub/ wheel bearing assembly. It may need to be replaced. Mine was causing the entire right rear to excessively heat up. It warped my rotor. It could probably cause the failure of a brake caliper.

 

I did rotate it as both tires were off and wheels were up in the air. Didn't hear any sound coming off of it, besides the brake pad scraping.