Rookie with Kandi 110cc brake system woes

[Steve-o]

Hello,
I'm a 501c3 volunteer working on parade machines for a non-profit group.
We have installed a Peerless Gear differential in place of the original solid rear axle so the buggy can turn more better during parades, (its a future parade rig).
This required that we support both axles near the differential pig. We also had to provide braking to both axles, both stop and parking brake systems. So here is the rub, sorta speak. We added another hydraulic line to the master cylinder by using a double banjo bolt. The banjos were located accurately with suitable thickness washers. We bled all four calipers with limited success. The pedal is wonderful for the front calipers. Outstanding performance with only 1" of pedal travel. The rears, not so good at all. The caliper cylinders move 0.10-0.15" with no pad movement. The bleeders on the rears are lower than the banjo connection so we bled through the banjo bolt several times. To date, we have:
Determined that the machine maybe never had functioning rear brakes
Replaced the master cylinder thinking that the piston was jammed
Adjusted the pressure rods for more movement on the rear system.
Tried only one rear caliper at a time
Tried only one pressure rod in place on the pedal linkage to the master cylinder
Considered leaving the buggy with the rear-end elevated over-night
Considered removing the brake switch and using it as a banjo connection for the rear brake system
Considered adding a second master cylinder, one for the front, one for the rear
Yup, its a long story,
Thanks in advance for your time and thoughts,
Steve-o

[tkeagle]

I'm no expert, but if master is not made for duel set up, you might need a 2nd one. Seems like always problems with braking with smaller buggy. They never have a over sized master. On yerfdog spiderbox a 2nd is required to set up a front and back. The 2nd master just piggy backs off the stock linkage.
Just sounds like your master not big enough to move that much fluid.

[Steve-o]

tkeagle,
We removed the brake switch sensor on the master cylinder. Then we re-threaded a standard banjo bolt with a 1/8-27 npt die and fastened the new rear brake caliper line to that port on the master cylinder. After much bleeding and such, the rear brakes work great.
So, the single port was not up to the task of supplying the two rear brakes and your idea put us on the track of trying another available port on the master cylinder. The next step if that failed, was to fix another master cylinder to the machine.
The brake switch sensor wires are re-routed to a vintage standard automotive brake switch on the brake pedal mechanism.
Thanks for your time and thoughts,
Steve-o

[SYCARMS]

That will not work. You need a master cylinder set up for front& rear brakes and a proportional valve. Some masters have them built in.