[Brad Townsend]

So I am back to chasing down my air leak and was under the coach looking for a drain on the wet tank and found it had an automatic drain. I pushed on the what looks like a stem valve to make sure it worked and it did no water came out only air.

I also noticed a horizontal tank not sure what it is, it looks to be about 4 inches in diameter and 14 inches long with a breather cap on top and a drain petcock on the bottom. I opened the drain petcock and nothing came out. Does anyone know what this tank is?. 

The 2 air tanks up front I opened the drains, the forward tank was dry and the other one had about 1/4 cup of water with a small bit of what looked like oil.

So on our way to our winter location we lost a brake diaphragm and had the whole chamber replaced.
I am wondering if there could be another diaphragm with a leak but can't detect it because it is inside the chamber housing. 

Yesterday I ran the engine and filled the tanks and now this am the supply is empty and the brakes have about 15 lbs.

I am planning to replace my old air dryer at some point this winter.