07' Freightliner cut airlines

I was wondering if anyone can tell me what these airlines are for? there is one larger supply line i have pinched off with vice grips to allow air to build and four smaller lines. someone cut them instead of removing them properly.

 

this is right above and in front of the front drive axle.

 

that was my first thought, but i was second guessing myself because there are 4 lines being supplied air and only one axle has parking brakes. i also considered air bags because they do not seems to be filling. the lines all shoot back towards front of truck. i will mess with it a little more and figure it out for sure but it is way to cold here right now.

thank you

 

I repaired the lines and that got the air bags, air seat, and differential lock to work. I don't understand why run the air line back and distribute to run right back into cab.