Brakes overheated, could the bearing be the cause

Last summer I drove about 20 miles to a a campground. The left rear got so hot it boiled the brake fluid (temporarily lost the brakes) and they were smoking. Drove home by stopping every few miles for it too cool off. Checked the disc temp at each stop with an IR temp gun. It got over 400 degrees by time I got home.

I'm thinking of just cleaning and greasing slides on the caliper (they've been neglected) and replacing the break hose.