First": TFLT please end the suspense and tell us what you did !
++++++++++++++++++++++++++++++++++++++++++
A couple of thoughts on late model tractor brakes:
Most if not all have 2 hydraulic brake circuits (one left and one right) very much like any simple older US automobile. Those often actuate mechanical wet brake disks internal to rear axles. Tractor Data says the 12sp version of the 7060 has "hydraulic wet brakes" and I have no clue what that is compared to the other wet brakes on non-12speed 7060's. Take a look at TractorData.
Is your 7060 in question a 12 speed and were the others with the disease ?
1) Many have "equalizers" between left and right brake systems. You said early in the thread that has been investigated already.
2) Some tractors (specifically MF2650-60-70-80 series which I own one of) come with factory-known deficient brakes (!!) I am not kidding even a little bit. Have you tested the 7060 on steep ground ? As delivered mine would not hold the tractor on a 40% slope. It was factory-equipped, as apparently all of them were, with "4 disc" brakes. After you force the issue they will tear the tractor down -- a major job -- and put in a "5 disc system" which will hold the tractor on a 40% slope. Since MF/AGCO will of course not comment, I must assume that they cynically build the tractors with lousy brakes on the statistical assumption that "most" users are on flat ground and will never catch them. Harsh, but what else could you conclude ? BUT THAT IS A DIFFERENT KIND OF ISSUE. My brakes never went to the floor.
3) I would jump on the "lets pressure bleed these" bandwagon EXCEPT that you found so many of the same model with the disease. This is wild. Surely Kubota would jump on this !!