Trailer airbags not inflating

Just noticed this thread is 3 years old. Hopefully OP figured it out. Lol

 

haha, i just realized i have the same problem. I've driven couple hundred miles apperantly with no air in air bags. everything looks good so far. I'll stop at TA in a few miles. hopefully easy fix.

 

yeah, that was me for last few hundred miles driving with no air in airbags just realized an hour ago i have this problem

 

The thread that won't die.

 

This is what it was on my trailer.
Spring brake valve, with spring brake priority.
It is designed so that when air is applied, it first fills the spring brake chambers. Once they are released, then it fills the reservoirs on the trailer, which then supply the air suspension.
When this valve fails, it still fills the brake chambers, but will not fill the reservoirs, hence no air to the suspension.
Sealco Commercial Vehicle Products - Air Products Catalog

 

Mine doing the same.. the front airbags are full of air the back are not. And the rear axle brakes lock up when you barely touch them.. $3000 later I can tell you it’s not airbags, brake chambers, the main valve that is on the tank.