Yeah, it's braking on the downhill and wheel gets incredibly hot and takes a while to cool down because its a significant thermal mass. Anyways, whenever I am going to drive in hot conditions on significantly hilly terrain, I'll disable the surge brake. I have a special piece of wood that I can insert in the tongue to prevent the damper from moving and subsequently engaging the brake. Obviously, do this only if your tow capacity is greater than the weight of the trailer.