Air Force One venting

[dp7]

Finished installing an AF1 system & tried it out today for the first time. All was as expected except that I was surprised at the amount of air being vented out the small brass port on the side of the control module. It is my understanding that air flow is used to generate vacuum via a venturi for the power brake booster in the towed. Consequently I expected some venting, but was surprised at the amount that flowed out the entire time the brakes were applied. Does it sound like I have a bad control module, or is this normal?

[BFlinn181]

I doubt it. The orifice is machined to create the vacuum as the rushing air draws air out of the system. I've got a vacuum 'pump' that uses the same design to make a vacuum, it vents quite a bit of air as it's working. As long as it doesn't drop your air pressure too much in the RV and the compressor can keep up, I think you're fine.