Motorcycle Repair: Yamaha Raptor, yamaha atv, yamaha raptor 660

Question
I have a 2002 Yamaha Raptor 660 and am putting new rear brake pads in and I tried backing the piston up using a c-clamp but it didnt want to go, and I also tried turning the piston and pushing but neither seem to do anything, Is there a special way you have to back the piston off on atvs?
thanks

Answer
MrHonda doesn't have a lot of input for your Yamaha ATV question, specifically.  Hydraulics are hydraulics, though, If the piston doesn't want to retract you have two options... open the bleed nut on the caliper and then use the c-clamp. If that doesn't work, use the master cylinder to pump the piston out of the caliper and then clean up the parts and replace the seal ring, after you have scraped all the crud out of the groove.

Bill MrHonda Silver