I posted this picture on another related thread where a guy found a similar piece in his air dryer.

I made it to Tulsa Ok today and started loosing air. I pulled over and noticed the new air dryer I just replaced in Johnson City TN was consistently purging air. I barely made it back to Tulsa without being able to touch the brake as the pressure was down to 80 PSI. Just as I pulled into the parking lot of the mechanics the emergency brakes locked up. We pulled the purge valve filter off the top and there was a little oil in it and some other tiny debris along with one of the three pieces in the photo. We fished that out and then pulled the purge valve off and two more pieces fell out. One of the pieces was stuck in the valve not allowing it to seat. The are the same pieces as in the OP’s picture above. What are they coming from? What is coming apart? Could these have come from the compresso?

