Classic/Antique Car Repair: brakes, rear brakes, proportioning valve


Question
I have a 68 GTO that I have replaced the rear brakes. Now I cannot get any brake fluid to them.  I have tried the hand vaccumn pump and the othewr person in the car, still no fluid.   I hae tried to break the lines apart and blowing air thru them, still no fluid.  I thought that there might be an air lock in the mc so I bench bled it and still no fluid.  I have after market disc on the front.  I have tried going from front to rear and rear to front, no fluid either place.  I disconnected the lines from the front and they appeared not ever to have any fluid in them, they were bone dry.  I have tried to reset the proportioning valve also.  I have considered taking it to a shop but would like to learn how to fix the problem without spending$$$.  One other thing the brakes worked when I parked it to begin the brake job.  Any ideas?    kevin

Answer
I assume that you bench bled the master cylinder and had fluid flowing from both of the line fittings on the master cylinder, so there must be an air bubble in the lines somewhere that is preventing fluid from flowing back to the rear axle fittings.

I use a pressure bleeder to avoid these problems, but that has to be done by someone who has the right equipment.  All I can suggest is that you open the line that runs from the master cylinder to the proportioning valve and have a helper keep pumping fluid into the line until you get flow that far.  Then hook up the lines to the proportioning valve and make sure you can push fluid all the way through from there to the rear - just keep at it, take baby step (meaning purge one line at a time) and you should be able to purge the air out of the lines.

Dick