The little R clip is inside the caliper and goes through the thinner pin. It sits between the caliper body and the back of the brake pad on the open end of the pin to stop the pin falling out. They can be a bugger to find if the caliper is dirty or corroded. I'll post a photo up and send a link in a minute.
![Disasembling a caliper (2) - Forums [Biker Match]](/images/backgrounds/strips/8mobileLQ.jpg)
![Disasembling a caliper (2) - Forums [Biker Match]](/images/backgrounds/strips/8desktopLQ.jpg)
