Brake servo vacuum system

Hi

My roomsters brake servo is fed from the manifold but the line t's off to the air box too. 

What's the use of this and what will be the issues if its blanked off so the servo to manifold line is essentially one. 

(yes I fitted a pointless ebay "cold air" lol induction kit, please don't judge I have my reasons)

Car has been fine on testing like this. 

Thanks

Edited 2 September, 20187 yr by Roomyster
Terrible spelling