FL Tag Loses Air

[NWIP]

Scenario is chassis aired up, pressures both primary and secondary at 135psi, no low pressure indicator on tag. As soon as selecting drive I hear air escaping and pressures drop on air tanks. If I am maneuvering at low speed, ie getting into or out of RV Park, I will continue decreasing air pressures and approximately 90psi I will get low tag indicator light. Once speed increases to above approx 15 mph I no longer hear escaping air and pressures return to normal.

Had this intermittent problem while in Alaska for 2 legs, then suddenly went away once I got to FL in Fairbanks. FL thought may have gotten dirt in escape valve not allowing it to seat fully. Just reappeared on last leg to Alamosa.
Normally run tag in Auto, have tried other positions with no change.

Anyone have anything like this happen or any insight. Thanks

[kenwyatt]

On my system in auto air is applied to the lift cans to raise the tag. After you reach the speed it’s set up for the air is removed allowing the tag to drop. I blew the diaphragm on 1 side and it sounds like what you are hearing. Manually lift the tag and look. Also there is a tattletale hole in the side of the can. You should not feel air coming out .

[NWIP]

Just wanted to follow up on loss of air pressure issue I was having. First I have had trouble getting info on how this system actually works as there is a number of components and rather complex as there is two different functions related to the tag axle.

One of the things that happens is tag air bags deflate unloading the wheels on tag axle. This function is controlled with the switch either automatically or manually.

Separately, there is also tag axle lock solenoid which unlocks/locks the tag steering, this is where my issue occurred. Solenoid continued to command unlock signal while under 17mph threshold allowing air pressure loss. The way it was explained is once unlock signal is sent to unlock the tag steering and accomplished air should stop porting to the valve. This was not happening😡.

FL replaced tag axle lock solenoid and all is operating normal. Covered under warranty😀 and I now understand a “little” more than before about the system.