New brake system - no pressure...

i had to bleed mine at the T junction on the axle
i also found that bleeding it then leaving it for a day or two then bleeding it got there eventually. the air migrates out with the changing temperature

other options pump the fluid in using a bit of threadred brass pipe instead of the bleed adapter like they do on motor cycles. you can do this with a diff oil bottle with a top of cap pipe. just hang it up upside down in the roof higher than the master. pipe from bottle to a sheel cylinder or caliper and the weight of the fluid moves into the system.
do each corner
or suck it through with a mitivac. again works better with a threaded pipe and plumbers tape than the bleeder,but doesn't necesarily move air caught in the upper corner of the calipers

All it takes is 1 small inch long bubble stuck somewhere in a pipe to give no peddle

as mentioned its worth adjusting rear brakes to locked on.. adjust back off again when done

Dave