CO2 dual primary regulator leak

So i have a leak in my dual primary CO2 regulator and i am having trouble diagnosing where the leak is. I tried the whole soapy water trick but no bubbles were seen.

I turned on the gas and set both regulators to 20 psi. I have the shutoff valves to each gas line closed. I then shut off the gas. After 24 hours the 2nd regulator (furthest from the tank) still reads 20psi. The first regulator (closet to the tank) now reads 18psi. After 36 hours the 2nd still reads 20 but the 1st reads 16.

So it looks like have a slow leak. Can anyone point me in the right direction where this leak is?

im having a similar problem. but with mine its the tank gauge thats dropping. if i shut off both valves and close the tank valve, after a day the tank pressure is at 0. i dont know how to fix it either. i hate applying soapy water over everything but im thinking thats what im gonna need to do.

The valve on the CO2 bottle is what's leaking, and it's supposed to.

When you close the tank valve, you are unseating the top of it. A CO2 tank valve needs to be all the way open when in use, because it seats at the top to prevent leaks. When you close it, you unseat the seal at the top of the valve, allowing the pressure in the regs to slowly leak out.

This doesn't necessarily mean that your regs/tank isn't leaking, but it's not a conclusive test. I'd say if you have no bubbles, you have no leak.

Lemme know if this doesn't make sense.

Double edit: this applies to both posts above.
Edit: Damn OCD, I couldn't leave it with my half assed explanation....here's a picture:

thanks alot. i love the pic by the way...

A picture says a thousand words - thanks shortyjacobs.

No problem. This brings up an important point....make sure that when you open a CO2 tank, you open the valve all the way so you seal the top seat and don't leak from there.