One rear brake locked and hot

Hello, I have a 2003 Chevy Astro van with a brake problem. One of the rear brakes is locked and when driving it (testing) it immediately gets very hot.


I have replaced the brake pads and lubed the brake system. Flushed the brake fluid and replaced with new.
But the brake is still locking and gets hot.
All of the other wheels are fine.
Any recommendations on what could be the issue and how to fix?



Thank you!