I have a Viair 480C with a 3/8 Check valve. It used to have a second 1/4 inch check valve going into my 5 gallon tank. Every thing was working fine.
I upgraded my tank to an aluminum one took the extra 1/4" check valve off.
Now the rattle is very loud and resonates in the new tank. I have a replacement ordered from another company to see if that cuts down on the noise.
Malodave