2011 Polaris Ranger RZR ATV Service Manual, Page 345Get this manual
BRAKES Caliper Assembly
= In mmRZRRZR S: Rear Caliper Piston O.DStandard: 1.1875" (30.16 mm) Service Limit: 1.186" (30.12 mm)
Install new caliper seals (A) in the caliper body (B)Be sure groove is clean and free of residue or brakes may drag upon assembly