what is this do?

[SuperPete]

Can someone tell me what is this vacuum line for?
I believe its dumping back to intake or picking up air from it?
I need to know for sure.
thank you

 

[Macgyver]

Vacuum for the brake booster and other devices.

 

[SuperPete]

DO we know if it's intake air or return air in to that hose?

 

[ZSHO]

That's used for vacuum reference IIRC.  Manifold - Vacuum Supply. Z

https://www.tascaparts.com/oem-parts/ford-brake-vacuum-hose-dg1z9c490b/?c=Zz1icmFrZXMmcz1oeWRyYXVsaWMtc3lzdGVtJmk9TVQwOTI3NjUmcj0xMyZhPWZvcmQmbz10YXVydXMmeT0yMDEzJnQ9c2hvJmU9My01bC12Ni1nYXM%3D