A few things to verify ...
All calipers bleeders should be on the high side, otherwise air will collect in the caliper.
The 3/4 to 7/8", is this pedal travel?
You indicated no pedal, does the pedal go to the floor?
With the engine running is there any difference in pedal travel, or feel?
I believe the Versailles e-brake is the type that pushs the pad into the rotor, if so try adjusting the e-brake gradually and see if pedal travel or feel changes.  If so, the e-brake needs to be adjusted accordingly.

I believe a 15/16" bore MC is a better choice.

It seems to me you've still got air in the system, and a little goes a long way.  You've stated you've completed all of the usual steps, but - no offense - it's another matter of doing them correctly.  For instance, it can be tricky to bench bleed the MC correctly and if you don't, you may never get all the air out of the system no matter how long you bleed the lines.  I've spent a long time pumping the piston in the MC only to find that one of the return lines lifted out of the fluid, or that it wasn't sealed to the plastic fitting and air was getting in the line.  ALso, some methods of bleeding the lines are better than others.  I've never had success using a vacuum pump and I'm afraid of using my Motive pressure bleeder spewing brake fluid everywhere, so I always use the old standby of having my son or wife pump the pedal while I open and close the bleeder screw.  So the only thing I can recommend is to do the steps over.  Also, make sure all of the lines are below the MC and that the proportioning valve is wide open so there is no restriction to the rear lines.

Last edited by jkordzi (5/20/2015 8:16 PM)

Thanks for the input - I used my vaccum pump to bring fluid to the rear and front - then switched to wife "down and up" method. Yes, MC can take a long time to bleed ( 60-70 pumps). I made sure bleeder tubes were submurged and not allowing air back into MC. Have done the above 3 times, Wilwood proportioning valve in the full "decrease" position. All lines are below the MC.

I agree that it acts like a bad MC, but it bench bleeds perfectly. MC is mounted to Bendix Booster in correct position, pedal geometry is correct with curved pin in position. I had a combo proportioning pressure differential valve set up originally - had the same result - no pedal. Discovered pressure differential valve had moved toward rear and would not reset due to a bad "o" ring. I went to tee and adjustable valve to see if I could get brakes - no pedal. I'm about ready to go back to single MC with drum brakes! LOL

Might be a waste of time but maybe you could pull the M/C forward and measure the total travel of the actuator rod in case there is something wrong in the booster and you could also verify that it is pulling back to the fully retracted position.  Something may be causing a hangup of the pedal or the pedal rod when installed.  Did you measure the .002" clearance on the bench before the install or when the booster was already fully mounted in the car with the pedal attached?  Is there anything that would prevent the pedal from coming fully back?  Can you pull on the pedal and pull it back a little?  Grasping at straws but sometimes a problem like this is so obvious that it is overlooked.  Sure seems like you have done your homework which would tend to indicate a failed component.

What is the final distance between the relocated brake pedal pin and the center of the pivot?

I measured push rod travel old MC vs new MC - on the bench. Total travel of old MC is 3/4", new MC is 3/4" but can be pushed to 7/8" max. I measured push rod travel at Booster - 7/8" max travel. Push rod returned to ready position by force applied by MC. Pedal returns to acceptable ready position. I know, this problem is driving me nuts.

Steve - Bendix Booster I believe a 67' - 69' ford mustang - thick unit with vaccum intake at top - I believe they call it a "banded unit". Will take pictures for bleeder's tomorrow. Please confirm that rear disc bleeders are at top NOT bottom.

GPatrick - Rubber lines in rear to calipers, stainless steel everywhere else - couldn't find SS for rear to caliper. Next try - I figured I would need to isolate front from rear and see what happens. I was hoping someone has had the same problem and had a fix. Thanks for all the suggestions. 

Don't forget you can use this old trick. Preferably a clear line going from the bleeder valve into a small jar of Brake fluid to see if there is air or fluid pumping out. This also prevents you from sucking air back, because of brake fluid in the jar.

I have seen similar symptoms three times once when the calipers were in the wrong position as MustangSteve suggested twice when the wrong pushrod was used. I know tracing down an issue with someone elses work can be frustrating but take a step back, breathe and you will realize that there is air in the system even a faulty m/c would let you "pump up" some pressure. Find a friend or a local parts guy and compare your pushrod, pedal, and mount etc. to a stock 65-66 unit you must use the '65 mustang pushrod period