Dr30 Rear Calipers - Pushing Piston Back

[Imago]

Hey guys.

I got a caliper here that I could do with a blown up diagram of.... But can't find anywhere.

My issue is that the piston won't return back, nor rotate (to screw back) so I can replace the pads.

Is this a common issue or am I just doing it wrong? I've put a lot of force on it, maybe not enough but I'm not too sure.

Tips, advice, pictures!

[GTSBoy]

I don't know if those one push or screw back. Have you peeled back the seal to see what the condition of the piston is where it meets the bore? If it's all rusty then it could be all over. Was this caliper in service recently or has it been in the shed?

[scotty nm35]

It looks like a screw back type due to the shape of the piston. It also looks pretty rusted up.

[Imago]

I tried to spin it with a pair of multigrips but couldn't get it to budge.

Its been sitting around for a while before I got to it, but it still had fluid draining from it when I got it, so it hasn't been entirely dry.

I'll make some more attempts but it may be a rebuild job...

[_x_FiReStOrM_x_]

Photos of the rear (handbrake section) would help. It's definitely a windback piston, some calipers do have a screw in the rear for winding back. Give the piston face a few taps with a hammer too, it helps to free them up alot of the time.