Decided to check out my rear brakes the other day, I usually grease up the slider pins and make sure they are working properly. One of them came completely off. I couldn't get it back into the caliper no matter how hard I tried. So, I decided to replace all of them since they are only a few bucks. The new ones seem much smaller in width than the old ones. They fit fine, but comparing them, the old ones appear to be swollen. Is this normal for the old pin boots to swell over time?