70 Duster power to manual brake conversion

Well, nothing is leaking from the line mentioned. I still can't find a single leak. I guess the next step is to clamp off the back at the flex line again and actually drive it to see if it indeed is a solid pedal when doing so. At least that would confirm 100% that the issue is still in the back. I don't know what would be leaking in the back though unless the flex line, only a year old, is ballooning, or the brake tee with the vent bolt through it is somehow leaking through into the axle housing.