Booste3rex

Hey guys Was going to bleed my breaks (they were not working wen purchased car ). The rears bled fine then when I got to the fronts no fluid... My pedal goes right to the floor. I checked my lines took them all out n everything . The prop valve is not allowing fluid to the front lines . Has anybody came accross this before ? And where can I find a new prop valve have looked everywhere cannot find a oem replacement anywhere, can I use another one or different one . I took out the prop valve tried blowing air threw but nothing gets to the fronts, I'm assuming perhaps just worn out. This is a 87 gxl that I hAve. Thanks guys look forward to hearing from people !