Scraping sound from left rear tire
 

That about says it all. I pulled off the tire and can see that the rear pads need replacement. The sound does not change while I am braking so I am guessing the problem is in the parking brake inner hub area. Maybe some part was come loose. It also gets pretty warm compared to the other side after a half hour drive. I have installed drum brake shoes on a Ford before so I assume this will be similar. I can't find any info on the rear wheel bearings in the Hayes manual. Do they need service?

Yes they do and they are easy to replace. Check first to see if the brake pads are rubbing and if they are in good shape. I think it took 15minutes per wheel for the bearings.

i dont know on the 123 but on the 126 the rears are sealed and require special tools to remove. unless they have play i would leave them alone.