[Richard]

Brad,

The travel solenoids are only energized when the key is ON, and the coach is in TRAVEL mode. If the coach is in LEVEL mode all solenoids are OFF unless the control panel tells one or more of the level solenoids to open.

[Brad Townsend]

So I turned the key to on position and put it in drive and checked out the 6 pack.
The 2 outside solenoids were magnetized so I guess they are the travel ones and there was air
being released from below the pressure regulator and the pressure went up to around 40 psi while releasing.
Shut of key and put in neutral air stopped releasing.
Is this air release common?

[Richard]

Air releasing from a regulator can occur if the pressure downstream of the regulator is higher than the setpoint of the regulator. Air should not continually release from a regulator.

How could the first scenario happen. When the coach sits, if the drive air bag system leaks just a bit, more weight will transfer to the tags with your setup. That weight bearing on the tag bags will generate more air pressure in the bag. When you open the travel solenoid, that pressure would make it's way to the regulator. BUT, if that is indeed happening, the leakage should eventually stop.

The second scenario is that the regulator seal or diaphragm has failed. That would result in continual air leakage and possibly very little air making it's way to the tag.

I hope this helps. Did it leak the entire time the key was on? Or did it leak and then stop?

[Brad Townsend]

I didn't wait to see if would stop but will do so.

[Brad Townsend]

It stopped but seems the rear of the coach has dropped to the max like the drive also was drained. Is this possible to drain the drive axle through the tag manifold?

[77newell]

I believe it is possible if the key is on and there is no supply air being added and the diaphragm in the regulator is shot. In this case the the leak would drain the supply until the PPV at the service tank closes and then the air pressure will disappear quickly. If the HCVS are trying to raise the coach the air will flow backward through the HCVs and back through the 6 pack and ultimately out the leaky pressure regulator. Air is sneaky that way, it will go wherever it can.

If there is air supply, engine or other compressr, does the regulator continue to vent air.

[Brad Townsend]

I will try running the compressor to see if it still drains tomorrow. I bet it does because if the air leaves the drive bags that should call for more air.

This might have been an ongoing problem just found out because I notice when traveling the pressure drops down quite a bit then comes back up.
Hmmm.

[77newell]

Rapid cycling of three compressor would certainly be a symptom of the leak Richard was hypothesizing. I have been amazed at how small an air leaks it takes to ra pid cycle my compressor.

[Fulltiming]

If pressure is dropping quickly while in driving, I would definitely check for a crack in a height control valve.

[Richard]

Brad,

What does your supply pressure do when you are parked and the engine isn't running? How long does it take it to lose say 20 lbs if the aux compressor is not running? The reason for the question is that would tell us which side of the sixpacks the leak is on.