The 73 classic brakes can smoke after the first landing on a new set.
Same thing on the 727. Had this happen to me more than once as well. Once at a US Air Force Base and we damn near got covered in foam from about a dozen fire trucks before I could get out of aircraft and stop them.
Even after told them why the brakes were smoking, they really didn't believe me until I went to the main gear and put my hands on the tires and then the brakes.