Repair Safety Notice:
This information is for general instructional purposes only. Vehicle repair can be dangerous.
Verify all information, follow manufacturer service procedures, use proper tools and safety equipment,
and consult a qualified repair shop when needed.
CARADIODOC
AUTOMOTIVE REPAIR CONTRIBUTOR
34,308 POSTS
With nothing else to go on, I have to assume the caliper has the parking brake mechanism built in. If it does, you need a special tool to rotate the piston to retract it. This photo shows two different versions of that tool.