99 freightliner problems

Hoping someone can help me out I'm on day two out of service. Started my truck Sunday Night ran for 30 or 40 minutes while I'm getting things around jumped in the truck and air buzzer was still on sitting around 20 psi. I knew my compressor was old so I changed the compressor and Governor today started the truck psi still sitting at 30 ish!! Crawled under the truck and air is blowing out of the bottom of the dryer not the relief valve but the purge. My son started pulling on the tank drains the first closest to the motor was pouring water the larger one behind that was pouring a muddy looking mess of water and oil. Drained those out until nothing could be seen coming out but air still not building and still coming out of the dryer!! When I would push up on the purge area air would slowly start building but not enough to make it purge. Any ideas? I'm already grand into this and two days down I really don't want to keep throwing parts at it. I'm already thinking (besides the oil in the tank) that my compressor wasn't the main issue. The other air Guage on the dash trailer or secondary whatever it's called was riding around 100 not losing or gaining. 12.7 Detroit engine incase that helps

 

I wondered the same thing. I had one years and years ago strapped a belt with a quarter ran it till it popped and never had an issue again with it. I should add that before this while driving that thing would purge every 30 seconds not while sitting just driving

 

Would stuck purge valve cause the water build up in the wet tank

 

I'm in the south so right now ice isn't an issue.

 

Isn't the purge valve located on the dryer? I'm just trying to learn as I go here