All but one sleeve on mine was seized... and as you know, a bitch to get out especially without damaging them or the rubber boots. With lots of PB spray, heat and choice words I managed to get all with only slightly f'n up two boots. Several pins were so pitted they shouldn't have been reinstalled... but I exhausted all my resources looking for replacements but could not find any... without buying the complete caliper. Don't look to be too hard to make so the next time I have one apart I will take one to a local machine shop and see about making some. For now they are all cleaned, polished as best they can, receivers all flushed and cleaned and well lubed with marine grease.
I just took my fronts off. First off, the brake pad does not sit correctly on the rotor, the outer edge of the pad hangs out over outer end of the rotor so eventually, as the pads wear, they will come into contact with each side, and no longer press onto the rotor. Will have to mill some of the pad material off the outside, or re-engineer the caliper mounting bracket so that the pads sit lower onto the rotor. That would take some doing (weld the threaded mounting hole shut, then relocate and tap new mounting holes).
I also had a seized sleeve on the right front bracket. Haven't gotten it out, yet. Sprayed some Kroil down in it last night and letting it sit. YOu could tell the rubber boot wasn't seated correctly so water had likely gotten in there and it's rusted in place. The pads on that side were in pretty good shape since obviously only the piston side was doing any work. Rear pads look new, but I wonder if there is air in the lines. Basically, it appears my left front brake was doing the lion's share of the braking on this machine. The brakes have always sucked.
As far as replacement parts, the chinese don't know how to create anything new, so these parts must be copied from some other machine, likely Japanese. What is the motor copied from? I wonder if it's the same machine.