I have a very distinct “rubbing” noise coming from the starboard side of my tandem axle trailer. I thought/think that I have a brake caliper(s) that is not disengaging properly. I jacked the trailer up and spun all four wheels with no resistance. I checked all the caliper bolts to ensure that none came loose. I even put my metal key in the actuator that the manufacturer supplied and took it around the block and it still made the noise. I checked the entire c- channel frame to make sure that there was no debis in the frame causing the noise. I’m puzzled...