Brakes nightmare.....

[snapper]

Had an issue with several master cylinders until I bought a new one.
I tested master cylinders 2 and 3 using bleed nipples in the 3 outlets, bleeding all 3 one at a time but never getting a firm pedal.
Tried the same with the new master, firm pedal and helps to bleed the master before attaching the pipes.
I put the first pipe on leaving bleed nipples in the other 2 ports, shortest pipe to the front and bleed till firm, then longer front, then single rear.
If you can't get a firm pedal when bleeding the rear, check the 3 or 4 way joiner, nip it up well, it often leaks a tiny bit, then bleed, nearest rear brake /shortest pipe to the joiner.
If there are issues at the rear you can use the bleed nipple method on the rear joiner.
Doing it this methodically will help you isolate a problem while having confidence in the previous work.