I have a 58 Ford Custom 300 2 door sedan with stock drums all around. Wheel cylinders were leaking so I replaced all 4 along with new front shoes and front hoses. The metal lines were all new a few years ago. While I was doing it, I went with a dual master cylinder for a 67-72 Ford with drum brakes and a 1" bore. I disconnected the rear brake line at the front junction (put a plug in that port) and attached it to the rear port of the master cylinder. I did put a T in this line to allow for a port for the brake light switch. I attached the existing metal line that went to the old MC to the front port of the new dual MC. Front and rear chambers are the same size on the MC. I bench bled the MC and trying to bleed the wheels and I have zero fluid to the back. Fronts seem to bleed fine. I checked fluid at the MC port, good. Checked at the T going to the back and there is fluid there. But nothing at all at the rear wheels, not a drop. With the MC I am using with equal size chambers, does it matter which line goes to the front or back. I know on disc setups, it matters but they have a bigger chamber for the discs. I hooked them up the way I did because the existing metal line reached the front port, but would have been too short to reach the rear. I can't imagine I have a plugged line or rubber hose going to the back. The brakes worked last year when I drove it but just had leaky, grabby cylinders. Any help? Thanks.
You are correct, it doesn't matter which reservoir serves which end of the car in your set up. It is rare but the flex line at the rear axle can get filled and corroded like a blocked artery. I have seen it. I would loosen the line at the flex hose and see if there is pressure there first.
When you get it sorted out you may find a hard pedal. A 7/8” MC can help with that or increasing the mechanical leverage on the pedal. I’m assuming it does not have a power assist. They work better with 1”and 1-1/8” MC’s.
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