Last night when i was driving on a local road my brakes failed. I noticed a banging noise from the rear right and I was sure it wasn't a flat tire. Luckily there weren't any cars in front of me and i was able to pull over. I drove about a mile running a bunch of stop signs and using the clutch to slow down.

Somehow the bolts holding my rear brake caliper came out. I guess they got loose overtime.

It's the same as what happened to this guy:
https://honda-tech.com/zerothread?id=2087452

Anyways, i'm having trouble trying to screw the piston back into the caliper. Should I have problems getting it back in? Do I have to get a new (used) caliper?

Thanks for your input.