@dang2407 posted:René I know this may sound like a lot of work, but why not replace the calipers temporarily with female bungs? This way you can eliminate the calipers...the bungs would need vents to bleed the system - a block of aluminium at each corner with opposing holes and the right threads...
I can also put the pressure gauge directly at the end of the rigid rear pipes to check the master cylinder, but I am fairly certain that it works perfectly.
Maybe I'll start with a dial gauge on the calipers and see if they warp.