Lost all my air pressure overnight?

Did you drain your air tanks before shutting down for the night? I did this once and one of the the drain valves stuck partially open, I always checked them after that.

 

Yes,.......I would say you have a air leak,.............

 

remember that a truck is made up of like 10,000 parts, and many of them are air related and control air pressure.

You can have a stuck drain valve on your air dryer, a leaky glad hand rubber, a leaky air bag, or other things. And then you could of bumped your shifter lever a bit and moved it just a small bit and allow air to leak.

But it sounds like you have an air leak

 

what type of truck? The older Volvos had push fittings that have O-rings that become brittle and crack. I installed compression fittings to get rid of the air leaks.

 

Reduce your pictures before uploading.

 

Maybe you had a active night..... A really bid lizzy.

 

there are so many places the leak can come from however, to isolate some of them, (if the problem continues), set both the trailer and tractor brakes for the night. If it leaks, it's in your tractor. If it's ok, its in the trailer and or gladhand grommet.
Most common place I've found these things are the glad hands. Improperly seated, bad grommet are most common.
Other place to check if it's in the tractor, is the bleed valves on your air tanks.