Brake question '90 LeSabre

['97ventureowner]

I just went through and replaced the brakes, (new rotors, pads , calipers, new brake lines front and rear.) When it came time to bleed the brakes, the front passenger, and rear driver's side bled fine, however, the front driver's and rear passenger side did not. When the brake pedal was pumped and then held down, and the bleeder screw opened, the pedal did not go to the floor,and no brake fluid came out of the bleeder. It held firm in it's position. What could be the problem? I was wondering if it could be the master cylinder or something else I overlooked while bleeding the brakes. Does anybody have any ideas about this?

['97ventureowner]

Upon further research and talking to my local parts counterperson at Autozone, I was told that there is a safety system set up in case you lose braking ability in 1 wheel. What GM did was connect the front drivers to the rear passenger side and the drivers side rear brakes are tied in with the front passenger side. This assures more even braking when you lose one line. Apparently the triggering mechanism located in the master cylinder needed to be re-set. He told me in order to do this you need to pick an end of the vehicle, (I chose the back brakes) and open both bleeder screws at the same time. You then "slam" down hard on the brake pedal to reset it. It worked great and we were able to finish the job.