Had to look up pictures to figure this one... (to figure out front & back)
Looks like you got it backwards, the front port should be the feed from the foot master cyl., and the rear should connect to the rear brake lines.
If yours matches the pictures I found for conversion kits, the rod for your hand brake cyl. extends forwards, and is pushed in by the lever.
So - when the rod is forward, the piston in the cyl' is in front of the 45 deg. port and fluid flows to & from the rear normally. When the rod is pushed in by the handle, the piston travels PAST that port closing it off. At that point it starts applying pressure to the rear brake cylinders.... Release the lever & the system returns to normal operation.