What is valve called that releases air from airbags on tractor?

I am on my phone and don’t have the best view of your picture, but what I can see looks like the arm for your leveling valve hanging down. It should be connected somewhere. This is a generic picture of a leveling valve.

 

Yes that is leveling valve, that open port is probably just the exhaust port. Leveling balve adjust the air in your air bags with that arm that sticks out. If the arm goes down in sends air to bags. If the arm goes up it exhaust air out. When arm is in the middle it just holds pressure. So when you put a heavy load on it puts more pressure in to keep truck at same height. Get it? It keeps the truck level, so to speak

 

If it is exhausting air out of that port then replace the entire valve. Even the monkeys at the ta shop can do that one. Just make sure they don't put it on backwards. .

 

yes

 

You might not have needed to change your leveling valve. Some are slow and they will hiss (purge air) for a couple of minutes after you stop until they settle. Your tractor AND trailer have one, which you might know already. My tractor one went bad this past year. They only replacement I could find is really slow to settle and it drives me nuts because it hisses/purges for a couple of minutes sometimes after I stop.

The open port on your old leveling valve is supposed to be that way. That's the exhaust.

 

Think of it like this:

That levelling valve is mounted to the frame and the arm attaches to the axle somewhere. The goal of the levelling valve is to keep that arm level. It does this by adding or removing air from the suspension air bags. Its how it maintains the truck's ride height.

When the arm is sloping upward from the valve, it wants to fill the air bags (inflate the suspension) in order to bring the arm back to its neutral (level) position. When the arm slopes downwards from the valve the suspension is over-inflated and it will be exhausting air to bring the ride height back down. The valve will be inflating/exhausting air all day long when driving. Some react slower and you'll hear them inflate or exhaust air for a little while after stopping. If its constantly leaking out the exhaust port non-stop, its likely the levelling valve has failed.

 

Not that this has anything to do with your drier purging
But since you changed your ride height valve did you make sure it was adjusted correctly for the correct ride height ?
Cause you'll have more issues if it's not a the correct height