Trailer airbags not inflating

All trailers I've been around are spring. But my experience on airbag truck suspensions if you've got a leveling rod it could be broke / pulled out. I break them occasionally on my truck suspension (Peterbilt AirTrac) and have re-welded, rebuilt, and replaced em. No way getting around it they break, especially if your trailers been off road recently before your failure.

 

Besides the leveling valve could also be the valve coming out of the air tank.

 

It's possible.....if it's a safety valve that won't allow air flow until it reaches 90 psi, i have seen these fail before.
To verify, you can remove the supply line at the leveling valve to make sure you have a good supply of air to the valve

 

Yep, like Floyd said. Check for air supply to the leveling rod, no air, keep looking. Some trailers have pressure protection valves that will not allow air to air bags unless system air is at a preset pressure or higher. I have also seen these valves get stuck or seized closed and not allow air to leveling valve. Some trailers also have pilot valves to automatically dump the air ride when you apply the parking brake, it may be stuck closed. Step one, inspect the ride height valve and linkage, then check for air supply and so on...

 

on the big tank under the trailer you will find a pressure regulator valve , it only opens when air pressure reach a certain pressure, they get stuck.
to test remove and bypass valve , then replace when this solves your problem.

 

Can you ride like that and if so how long

 

That will put you out of service.

 

Until you wear holes from them being crushed by the weight of the trailer.

 

With my Utility I always had to be careful when sliding the tandems. If I slammed them hard all the way to the back it would pull against the airbags and somehow flip the level valve linkage to where the air bags would not re-inflate. I had to twist that linkage back into position. I would almost bet you $100 if you crawl under there and play around with that level valve it will air your bags up. Then it's just a matter of setting it back in the right position. I always go real easy any time I put the tandems all the way back. I see guys slam them and cringe. I even see people pulling air ride trailers with bags deflated on the highway. Some of them may have forgotten their manual dump valve but most 53 vans anymore don't have a manual dump valve.