Chevrolet: ABS Brakes, abs brakes, cavilier

Question
My step son has a 92 Cavilier z24 and he has problems getting it to brake.  He has changed out the Brake booster, master cylinder,bled the brakes and still little to no brakes at all.  He thinks that the front right caliper might need changing and also a ABS module plug right off the master cylinder he thinks might be bad.  We both are at a lost as to what it can be.  He has even taken it to his automotive class at tech school and the instructor doesn't seem to know what the trouble could be. We sure could use any help you can give us.
Thank You
Richard  

Answer
Hi Richard;
          Brakes - ok  well by replacing all of those parts it will take some time to get it to bleed right, for a good pedal . The car should be running when being bleed- Are the brakes being bleed from the r/r, than l/r - than r/f than l/f , and thay should be done a few times at each bleed. than the master cyld last and , it should be running when the master cyld. is being bleed, and you must keep adding more fluid because if you run out or the master cyld. goes empty you will have to start all  over again - you must get all the air out , Also was the new master cyld. bleed in a vice prior to getting put on ?
if the wheel cyld. are bad thay should be replaced or are any leaking , if not than thay should be ok. When it is running the booster will be working and it should bleed fine, and if you have a bleeding tank that is even better. good luck