The reason I was messing with the thing was that I was replacing it because of broken nipples at the check valve. This is a bit like the story of Edison asking a newly minted engineer the volume of a light bulb coming back a week later to finding working out the complex mathematics and asking him why he didn't just fill the bulb with water and measure that.

I had the old check valve which I dissected. The check valve connector come before the check valve. This makes Junqueyardjim and Diesel911 correct. The small tubes "see" the vacuum pump without a check valve and they have very small orifices. I'm not sure if they are the same size because I may have enlarged one of the holes. Let's make them approximately the size of a sewing pin, the type that women hold fabric together with when sewing.

My guess is they are the source for a lot of the rest of the vacuum system in the car.