can compressor be "stuck on"

This is sort of an update to my air dryer purge problem. Ive plumbed shop air to my hose that comes out of the compressor. I start the truck, and then turn on shop air. Once the systems to pressure, it purges. Ive also pulledcthe line off the compressor coming from the governor. I'm getting pressure there. Hook that back to the compressor/unloader, and don't feel any difference in the pressure coming out of the compressor-like it was being "shut off". I pulledcthe new unloader out of the compressor, stuck my finger down in there and felt "carbon" looking stuff at the bottom "seat". I wire brushed it out, reassembled, it acted better and then did the same thing. SO, after all that said, lol, is it possible that the internals of compressor are bad and causing it to never unload/shut off, or is that not really what's wrong

 

Awesome. Thanks for the responses. Im in the process of swapping out tuec1/4" line just to be safe. It is a d detroit egr s60. So at least now I have part#s and a sense of direction with it