I'm envious of you guys with brakes. My slave seals will leak into the rear axle in a couple of days last I tried. I even tried filling the masters with Lucas hydraulic oil leak seal. It's as thick as STP. Leaked right into the rear axle. When I got the tractor the axle was about 5 gallons over filled from them dumping oil in it.
I have heard this is caused from using the wrong brake oil and overtime it destroying the internal seals.
I was happy to find out it was a master cylinder issue for mine not internal to the rear end, otherwise I would not have brakes haha