Cameron

Hi i have a Escort RS1600i that has had a rear disc conversion done on it, but when i bought the car it was not running now that i have it running when the breaks heat up they all bind on. I have changed the fluid 3 times and taken all the callipers off and freed but they still bind on when heated. Does anyone have any idea what this could be???
Would the master cylinder reservoir be a 2 part or is the standard reservoir ok to run rear discs i,m unsure if the previous owner took it off and put a standard one on before i bought it. And Does anyone know what master cylinder would fit this car for rear disc that,s probably going to be my next job.
Thanks.