29-12-15, 07:29 PM
The problem with these calipers is that the small drain holes at the bottom get blocked and all the salt and crap from the roads get stuck inside the caliper. It soaks past the dust seal and corrodes the seal housing (as Deefer66 already stated).
The reason Fzs1000 option works well is: the pistons are the same diameter no need to change the master cylinder (both fzs1000 and 600 rear master cylinders are identical) and there is no well to hold the road crap because the pads are inserted from the under side of the caliper.
I would cut your losses and get a fzs1000 replacement. Judging by the level of corrosion on your caliper and the fact one piston is stuck, the seal seat damage may already be a factor.
The reason Fzs1000 option works well is: the pistons are the same diameter no need to change the master cylinder (both fzs1000 and 600 rear master cylinders are identical) and there is no well to hold the road crap because the pads are inserted from the under side of the caliper.
I would cut your losses and get a fzs1000 replacement. Judging by the level of corrosion on your caliper and the fact one piston is stuck, the seal seat damage may already be a factor.