2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 352Get this manual
BRAKES Sportsman Rear Pad Removal
1Support the machineRemove the rear tire2Remove the slide pin clips from the slide boltNOTE: When removing caliper, be careful not to damage brake lineSupport caliper so as not to kink or bend brake line5Push caliper pistons into caliper bore slowly with pads installed6Remove the caliper slide pins and remove the brake pads from the caliper
3Loosen the slide pins with hex wrench