Purge valve keep going off

[dieseltech00]

Air leaks can cause moisture in your tank as there will be more volume of air going to your tanks. Moisture is in the air so more air equals more moisture. More volume of air will also mean discharge line and air dryer will be hotter which will make the situation worse. However I personally haven’t seen air leaks cause excessive amount of moisture. If you’re getting moisture in your tank you need to replace your cartridge. If your truck is not losing pressure over night I doubt an air leak is your problem, But the following items could still be leaking as they would not drain the tanks. One thing you need to check is your hose going from compresor to air dryer. I would be surprised if it was plastic air line. When them braided hoses get old they can start to leak through the side but you won’t hear it when truck is running. Grab a 1” wrench and take the compressor discharge line off, get a flare fitting and some adapters and hook shop air up to the discharge hose to fill your truck with air. Then get that discharge hose soaked in soapy water to see if it’s leaking. If that’s good then you need to check your small air lines on governor going to both the air dryer and compressor like JimT stated. Check for leaks or kinks. Next you need to check and make sure your air compressor unloading valve is working properly. With your compressor discharge line disconected, start the truck. You should be able to feel air coming out of the discharge port of the compressor. Then with truck still running put 120ish psi shop air to unloader port of compressor and make sure no air is coming out of discharge port. If air is leaking past unloader valve is bad.

B2 Bendix document library is also a great free resource. This info is just my opinions. I could be wrong.