Originally Posted by cobalt327
One line to the rear split at the rear end is fine.
Have you verified there's no rear brake proportioning valve in the MC? Is there an added-on adjustable prop valve?
The valve in the master cylinder would be a residual pressure check valve which does not provide the same function as a proportioning valve.
The residual pressure check valve in a drum brake application keeps the return springs on the brake shoes from retracting the shoes away from the drum, and keeps the seal on the wheel cylinder pressed out against the bore.
As to the re-bleeding of the brakes, what I am attempting to determine is whether the amount of fluid coming out at the various points is constant. Example, good flow right at the MC, good flow at the output of the combination valve, poor at the calipers. It can help to determine problems.
Also, it isn't surprising to find air trapped in a brake system that has been thoroughly bled. It won't hurt to go through it again starting at the MC. If it is indeed thoroughly bled it won't take but a couple of pumps at each point to confirm it. Also, make sure you have a helper working the brake pedal and don't just depend on a vacuum bleeder or pressure bleeder alone.
Another thing to keep in mind, is that until your brakes are bedded in, you won't get maximum stopping performance. Also, unless you are moving pretty fast you may not get lock up on dry pavement when you have wide grippy tires. That is why trying them on gravel (if you can) or wet pavement is a good indicator of what is going on.