Air dryer wont Purge

You should have an unloader valve in the air compressor that could be stuck. Also you could have a leaking governor line to the tank or the discharge line could be leaking that bad.

 

I bet you got a replacement governor that has three ports and the control ports are reversed. I had the same issue with my first truck, it would not release at the air dryer and I played with it a bit, switched the control line to another port and it worked.

 

I had the same problem, I had the lines reversed. I was pulling my hair out after replacing the dryer trying to figure it out.

 

Since you are talking about air dryers, other than changing the filters twice a year what routine maintenance are you doing if any?

 

That's good to know, I forgot about cleaning out the lines.

Twice a year for a desiccant change out, really?

You guys work in the tropics?

 

Louisiana in the summer is close to it! I would rather spend the 20 extra bucks and err on the side of caution if it will prevent a problem. Use my drain chords daily as well. One freeze up on a dump valve was all it took to make me a believer.