Our Yamaha has been standing whole winter outside under blankets. Plan was to change new off road tires to it before season starts. When we took wheels off and changed tires and finally tried to install wheel back to bike it was not possible to get wheel back as brake disc didn’t fit between pads.
We tried to push brake pistons back, but those didnt move at all. Once brake caliber was removed it was noted that it was quite bad shape and there was plenty of dirt etc in it.
As we can see pistons are way too up and there is plenty of dirt on those so no wonder if those are not going down as expected.
So first we clean brake caliper using brake cleaner and tooth brush. Pistons might be quite tricky to get out from caliper, but I was using compressed air as seen in this video in youtube: https://youtu.be/ZoOh0h-YsO4?t=228
Once pistons were cleaned and all places in caliper it was time to get everything back again. Use Brake fluid to lubricate pistons before you insert those back to caliper.
Insert brake pads back and insert caliper back to bike. Finally we take air out from system and we are ready to ride again.
