Rear Caliper Assembly
 

Due to some unfortunate circumstances I recently had to have replaced my rear driver's side caliper and it ended up coming loose while I was driving and the piston was forced out of the seal. Someone I know had a look at it and removed the piston and gear bolt and wanted to put it back inside the 'dust seal'? but found a tiny snap ring or something that came out when the gears were unscrewed. I was wondering if anyone knows exactly how it fits back inside and if the caliper can just be reassembled.
https://cimg3.ibsrv.net/gimg/www.maz...475157594d.jpg
Originally removed from car.
https://cimg1.ibsrv.net/gimg/www.maz...1355f64ff0.jpg
Gears and piston with seal and snap ring?
https://cimg4.ibsrv.net/gimg/www.maz...cc88717d9c.jpg
Main caliper assembly.