Dryer Purges every 10-30 seconds

On the AV955205 dryer (which is a Wabco purge regeneration style), you need the have the PCCV valve installed in place of the secondary check valve. Did you do that? If that valve is not installed correctly it will purge a lot.

If that valve is installed correctly, you most likely have an air leak. If your gauges do not show pressure loss you leak is on the wet tank side (compressor, dryer, governor, wet tank and any hoses between those. Compressor unloaders can leak internally and not be heard.

 

Since you did the process of elimination, than it seems the Dryer was the problem.

 

I'm convinced

 

Nope. I would not be that in-considerate. Just that here in Florida, our humidity is super high most of the time, causing the dryer to work much higher.

 

Happened to me!

 

If your secondary tank check valve was replaced with the PCCV included with the dryer, then it's the dryer. If it doesn't have it, installing a genuine Wabco dryer will do the exact same thing. Read the instructions very carefully. If your truck already had that valve, replace it with the new one, it may be faulty. If the secondary tank only has a check valve, take it off and put on the PCCV.

The way that dryer works is after it purges, it regenerates the desiccant by allowing air to back flow through it for about 30 seconds. This will drain your wet tank to compressor cut-in pressure and start the cycle over again. The PCCV is a check valve up to about 90 PSI to protect your secondary tank pressure. Above 90, it will allow air to flow backwards back to the wet tank. This gives the wet tank the extra volume it needs to complete the regeneration cycle without turning the compressor back on.

 

Air dryer purging has nothing to do with humidity, and everything to do with air leaks in the system or defects in the air system.

 

That is 100% correct.