Hmmm...air leak.

[dhirocz]

So I just spent some time looking into my dryer more. Apparently it's acting as intended, and there are no factory installed check valves. That's news to me. I did see a schematic saying I could add one.

The info in the dryer says it will only let one side bleed down, and the other should stop at 70 psi, which it does.

Since my air supply comes off the supply tank (the valve I use to pressurize tank trailers to unload) which also drains the primary tank, it looks like I'll add a check valve in between. If it then drains the secondary, I'll put one there too. To double check myself I'll give Bendix a call on Monday to make sure this doesn't interfere with the operation of the dryer...they only show the 'optional' check valve on one tank, not both.

No factory installed check valves...wow. Thanks for pointing me in the right direction!