[Gnawrocki1]

Still working my way through the air systems. I'm hearing this sound (in the video) from the air tank in front of the passenger drive axle. Does anyone know what it is? My suspicion is it's letting air out, but I would like to really know.

Having trouble posting a video, but the sound is occasional pinging. It lasts for a second and happens every 10 seconds or so.

I am going to guess the sound is air flowing past the check valve that is mounted right next to the tank.  I had that issue and replaced the check valve.  The sound went away for about a year, but every now and again I hear it again.

[Richard]

David,

The tank in the passenger drive wheel well has a check valve installed on top of it. The purpose of the check valve is to allow pressure from the 120V or engine compressor to flow into the feed for the slide seals, potties, and air doors BUT block the pressure from the 12V compressor from trying to fill all the suspension and brake air tanks. That check valve will chatter when air is flowing through it.

[RussWhite]

What Richard said. I kind of thought of it as a whistle, but the important thing is that when the aux compressor shuts off, the noise goes completely away.

[David and Teresa]

David,

The tank in the passenger drive wheel well has a check valve installed on top of it. The purpose of the check valve is to allow pressure from the 120V or engine compressor to flow into the feed for the slide seals, potties, and air doors BUT block the pressure from the 12V compressor from trying to fill all the suspension and brake air tanks. That check valve will chatter when air is flowing through it.

Does this happen when all air compressors are off?

[Richard]

No

But if there is pressure in the system, then this could be clue about the air leak. If there is pressure in the system AND the check valve is chattering, the air is passing into the sub system that supplies air to the potties, doors, and slide out air seals. Meaning, the leak is in the plumbing around the 12V pump, the regulator, air lines leading to potties, doors, and slide seals.

[David and Teresa]

No

But if there is pressure in the system, then this could be clue about the air leak. If there is pressure in the system AND the check valve is chattering, the air is passing into the sub system that supplies air to the potties, doors, and slide out air seals.  Meaning, the leak is in the plumbing around the 12V pump, the regulator, air lines leading to potties, doors, and slide seals.

This is what's happening. There are no leaks in the rear door or toilet. I have 2 doors to check. I've taken the 12v pump out and closed the line and no leaks there. I need to look at the regulator I guess. It's a pretty good leak, about 10lbs in 5 minutes. I can sit and watch the gauge move down.

[Richard]

Yeah, I have had to replacemthat regulator due to leaking.

There are a few lines leaving that area to feed the doors and potties. You could disconnect and cap the feed one at a time. Or do it the redneck richard way and pinch the line with the smooth jaws of visegrips. Or do it the Steve Bare way and install the isolator on the airlines one at a time to narrow it down. There is simple work to be done right around the pump that can save hours removing interior panels