I had a similar problem on my trailer. Both right side hubs would be very hot. They found that the brakes were activating too soon and braking harder on the right than the left. In fact I noticed that often one wheel would lock up durning slow manuevering and light braking.They replaced the magnets and then the whole backing plates, no better. Finally found the brake drums were machined wrong, the machined hub surfaces were not centered with the brake drum machined surfaces. They replaced the drums and all works perfect now, no hot hubs/drums.
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