I am back from my month long travels. Lets go back in time 5 weeks ago...
After my failures to get any of my 3, IIIPro calipers to work on the back of the bike, (Several of the same calipers could be bled on the bench and were working), I took a super careful look at the ferrules on the rear, internally routed, brake line. I could see scrape marks on the ferrules from all the swapping of calipers and lever assemblies. Just for grins, I cut off the existing ferrules , removing the bare minimum of housing, and installed new ferrules and nuts.
OMG, I was able to actually bleed the rear brake and started getting decent caliper pressure. I took the bike out for a spin. Yuck! no stopping power. Brought the bike back in, sanded off the rotor braking surfaces, took the bike outside again - better, but not excellent stopping power.
I was running out of time to get this bike working before my trip.
For shits and giggles, I installed the caliper that I had rebuilt and installed new seals. See previous posts I bled the rear brake assemblies again, moving all the parts in multiple positions, tapping the lines, to try to get every last bubble out. Then...
WOW! the brake lever feel and caliper movement was fantastic!!! Took the bike out for a spin and the rear brake stopping power felt fantastic!
I decided to take a risk and use the bike on my planned 500+ mile bike camping/packing ride. Guess what! Brakes worked perfectly for the complete ride. Riding through, rain, mud, dust, across creeks, bogs, wet tall grass.... No problems.
Maybe they can be trusted....