Chevrolet: brakes, disc brakes, brake job

Question
Roger..
I have a '68 pontiac with disc brakes, after market on the front and drum on the rear.  I recently did a brake job on the rear, the brakes worked when I started.  After doing a complete replacement of all parts on the rear and then attempting to bleed them, I get no fluid to the rear, only air.  I have tried to bleed the front and did manage to get some out.  I have tried and tried to bleed them to no avail.  I have tried bench bleeding the master cylinder thinking that I might have sucked some air in the line and have gone from front to rear and front to rear with the same results.  I do manage to get some out of the front brakes, not as much as I should if I want to flush the entire system.  I have reset the proportioning valve and that doesn't work, still just air to the rear.  I am getting frustrated and am about ready to take it to the brake shop but I would like to fix it myself, you don't learn anything if you take it to the shop every time something goes wrong.  So if you have any ideas I would certainly appreciate the help.  Thanks for your time.....Kevin  

Answer
Kevin ;
 Hea- do not get up-set , you still have air someplace. I would first check to see that you have no leaks in the  rear wheel cyld. and in the front calipers.  also check that all bleeders are tight. than the mast. cyld.  - than
fill the mast. cyld. with brake fluid and start from the r/r brake  bleed it till you get some pedal ,tighten the bleeder.than re fill the fluid up and do the l/r and do the same. than go to the r/f fill the fluid and than the l/f  just keep the fluid full at all times as it only takes a bit of air to mess it all up on you. and bleed the m/cyld. too if need be. than if you have to re-bleed it the same way all over a second time,or till you get it right. It would be a lot faster  with a bleeding tank if you can use one.  you have air in there it will come out.  ok >>