high pressure flow noise on acceleration?

[Cyberwares]

First post! But I've been restoring a 99 5.2L single cab 4x4 Ram over the last few months and i'm nearly done with it. The one thing I cant seem to figure out is where and what this noise is. It happens on acceleration, but not all the time, and I mainly think it's when the engine is cold. It sounds like its coming from inside the cab and under the dash. As far as I can tell its not causing any issues, but I dont think thats a normal sound so I would like to fix it before it became an issue. It kind of ruins all the effort I put into laying sound deadener throughout the entire cab lol. It sounds like some sort of high pressure flow thats being restricted, or some kind of high vacuum pull through a small opening? Any advice is greatly appreciated!

 

[crazykid1994]

Does your ac function properly? The ac uses a vacuum switch to control the function. Any chance it’s the ac lines either? Or the heater core. Just shooting out a few ideas as I have no clue.

 

[Travelin Ram]

Vacuum leak into the brake booster?

 

[2012RAM1500RT]

Disconnect and plug your hose going to the brake booster and also the vacuum hoses that goes through the firewall that controls your heat/ac controls and see if the noise stops.