Question on CDR Valve

[Sparks-IDI]

I assumed the CDR valve, was a check valve in one direction. When I took mine off, I can blow in either port, and it is free flowing both directions. This does not sound right. If it is, I don't see the point of the valve. Just use a piece of pipe or hose to go from valley pan to back of the intake manifold. So is my CDR valve bad?

Logically, to me having it checked so intake manifold pressures cannot pass back to the valley pan, makes sense to me.

I bought the valve on ebay several months ago, so it is not an old unit.

I have been seeing a lot of blow by and oil leaks, and am trying figure where the oil is coming from.

 

[Nero]

The CDR free flows under normal conditions. Under high intake flow, there's a diaphragm that's held open by a spring that closes. There is a pinhole vent on the back of it.
It is not a PCV, so it doesn't have a check valve in it.

 

[Clb]

Nailed it