The adapter fitting betwen the MC and brake line is larger for the disk set-up then drum. Go here: http://www.championtrailers.com/DISC_BRAKE_INSTALLATION_ARTICLE.HTM
MY BRAKES ARE OVER HEATING
Disc brakes normally run hotter that drum brakes due to partial contact of pad and rotor during normal highway travel; whereas drum brakes have a return spring that retracts the brake shoes with virtually no contact between the shoes and drum.
Your disc brakes during normal highway travel should be "very warm", but still allow you to put your hands on the hub without burning. However during frequent braking periods, such as stop and go braking, they may be to hot to touch.
NOTE: IF BRAKE HEATING IS EXCESSIVE, CHECK THAT THE HOLE IN THE BRASS BRAKE LINE TUBING ADAPTER IS NOT OBSTRUCTED.
Also be sure that the master cylinder tubing adapter orifice is bored to a minimum of .0625" . This will facilitate the return flow of fluid to the master cylinder on the return stroke.