Little air leak

Coming out of here:



Which is located here:



Hissing right where the green hose connects into the firewall panel thing. If I wiggle it just right, it stops hissing, but then starts again.

I'd like to fix it myself, but don't want to just start ripping out hoses randomly while I'm under a load.

Any advice how to fix it? New hose, new fitting, or maybe just pull and reseal?

And as a bonus, what does this green air hose do? Trying to slowly learn my truck by whatever thing breaks next.

Thanks, ya'll

 

Nice. Thanks for the info. Maybe I'll mess with it tomorrow at a TA, so if I really eff it up I can go cry to them for help.

 

Yooo, that's a great advise. I always struggle with these little releases because I've been fighting against all the hissing and pressure. Now I feel dumb.

 

I tried pushing on it and it does stop hissing while I push, but starts hissing as soon as I let go. I haven't tried to totally pull the hose out and click it back in, I'm at a customer in middle of nowhere Texas and don't want to accidentally mess it up into complete inoperability. This line looks important ish, like maybe it goes to the red and yellow brake valves in the cab. Gonna wait until I'm at a TA or something to try.

I like trying to fix my own truck on the road, but I'm still inexperienced enough that I prefer to have a shop within walking distance when I do it if I have that option...