[Tfrazier]

Have thought and rethought everything about this install. The first picture is of the setup between the braided hose and the T, where the 3/8" airline comes in from the 110 compressor. The check valve is circled.

My question: could a bad check valve cause the supply side to lose the air? I have ordered a new one but just trying to see if anyone has an opinion on this?

Thanks

[Tf175]

It almost sounds like the engine driven compressor isn't producing compressed air . Like the unloader valves are activated . 
Evidently the system was working previously , you had found a leak at the pop off valve in the Brakemaster? 
In your pictures you have a hose with white arrows . That 1/4 hose goes from AD 9 to governor via a tee that also heads to the compressor  with a braided hose . The governor controls the unloader valves in the compressor,  allowing compressed air on demand . 
Your post states no leaks , have you felt at the bottom of the AD 9 with engine running ? Purge valve could be leaking even though it's a new unit.

[Richard]

Ok, you obviously have a massive leak somewhere. My guess is the purge valve also.

Please confirm the 3/8 black line is from the 110v compressor. We talked on the phone about how to confirm that.
When confirmed, turn on the 110V compressor, if the purge valve is leaking you should feel it or hear it at the bottom of the dryer assembly. The reason I am suggesting using the 110 compressor instead of cranking the beast is that hearing is a bit easier without the Detroit rumble.

Is is possible you have the control lines to the dryer reversed?

The fact that your brake pressure gauges remained at 50 tells us your Pressure Protection Valves are working.

Further diagnostics would be to disconnect the air line from the engine compressor, and crank the engine. There won’t be any doubt if air is coming from the compressor or not.

[Tfrazier]

I will try to answer the questions and be more descriptive. Also included a picture of the AD 9 setup with colored arrows and a description of how it is plumbed.
1. @ Chris: The black 1/4" hose in the picture of the original set up was a little hard to follow. It went directly from the governor to the unloader port on the breakmaster (kind of hard to see the termination on the breakmaster as it is at bottom on the back side). Hopefully you can follow the route easier in the AD 9 set up picture. It goes from the governor to the control port on the AD 9. The hose is a bit longer than it needs to be but I didn't feel like cutting it down.

2. @Chris and Richard: No Leaks. Confirmed that there is no air coming out of the bottom of the air dryer. I could only check this with the engine running as I could not get the 110 compressor to come on (further explained in number 3.)

3. @ Richard: Blue 3/8" airline that terminates at the T, between the braided hose coming from the engine compressor and Supply port. I have not verified that it is coming from the 110 compressor. Believe it or not, I can't figure out how to turn on the 110. I normally leave the switch in the on position and comes on automatically when I am in level mode, and the system needs a little more air added. Doesn't happen very often but I have never had the need to turn it on manually. Just my luck.

4. Control lines reversed: I don't think so. I pretty much replicated the set up that was on the Breakmaster. the Delivery port on the AD 9 is at the bottom instead of the top like on the Breakmaster. Also, the first time I tested it yesterday, everything functioned as it should. I started out with no air pressure and the pressure built up to 130 psi and purged just like it has always done. I assume if the lines were reversed, it would not have done this.

5. Removed airline form engine compressor, cranked the engine, tons of air coming from the compressor - no doubt about it.

I also performed another experiment today. I wanted to see if I could repeat what happened yesterday. This morning, I let all of the air out of the system. Around lunch time, I started the coach and sure enough, it went from no air pressure to 130 and purged. I then shut it down and waited an hour. This time the brake and supply side were down to 110 psi. I started the engine, expecting the supply side to drop like it did yesterday. This time both gauges remained at 110 psi. No drop in pressure but no increase either. So I decided to wait another hour and repeat the process. This time both were down to 90 psi and neither changed when I started the coach. So the last time I check them gauges was at 7:30pm ((9.5 hours from when I did it the first time this morning). Both gauges down to 70 psi, but again, neither moved when I cranked it up.

I going to have another look at the gauges in the morning and see where it stands after 24 hours.

   

[Tf175]

Your plumbing to the AD 9 is correct in comparison to what I have.  The other plumbing is different,  but it has been working .
It seems like you may have two issues :
An intermittent leak somewhere .
Something preventing the system from building pressure. 
My coach will leak down on the supply side overnight  when mostly parked .
When on a trip the system will stay up , sometimes 3 days , so operation helps a valve somewhere that I have not found .
 As your engine compressor is obviously working , I wonder if the governor is the problem . I don't believe in replacing parts until a problem is solved , but the governor is not a huge expense , so you might get a new one and try it. 
 Still , it seems everything was working prior to chasing the leaky pop off on the original dryer/heat exchanger .
Chris

[Tfrazier]

Just a quick update. Checked gauges this morning. Supply side down to zero, brake side at 50 psi.
I am going to replace the single check valve between the T and the braided hose. Not sure if it will make a difference but a new one was only 12.00 on ebay. Should have it by Friday.
anyone know the part number for a replacement governor? Suppose I could try this as well.

Thanks

[Tf175]

Look on the governor , ID tag may still be on it . It's a Bendix part , I'm thinking D-2 . I sourced my replacement from Ebay , can get the exact P/N this evening . 
Chris

[Tf175]

https://www.anythingtruck.com/product/060-275491N.html
Read the details section on this page .

[Richard]

So let's get up to speed on some of the fundamentals of the air system as used in the Newell world. The engine compressor supplies air from 90 to 120 psig. The governor talked about controls this. If you are goint to 130, I would think about putting in a new govenor. The 120 AUX pump is normall set at 70 to 90 psi, so it won't come on in normal operation of the coach. However, HWH has wired a bypass into the pump control system that turns the 120V pump ON when the leveling system calls for air. There is also a 12VDC pump that is set usually from 50 to 70 psi. Unlike the 120V Aux pump, it has a check valve that prevents it from airing up the entire coach. In your case it will pressurize the potty and the air doors.

Look for the switch for the 120 compressor either by the microwave or in the front cockpit. Sometimes there is a switch for the 12VDC pump in the bathroom. Convenient for flushing the potty.

Supply side to zero indicates a leak somewhere obviously. Brake side at 50 says your pressure protection valves are doing what they are supposed to. Their purpose is to prioritize air in the brake tanks. Most are set to maintain pressure at 60 psi. So the main leak is NOT in the brake system.

Have you put soapy water on all the connections you touched?

[Tfrazier]

Just repeated the process to verify what the gauge is reading when the system purged. I did it twice and both times it was just short of the 130 mark on the gauge. Will verify part number and order a new governor.

@Richard: your comments about the 120 Aux pump and the 12VDC compressor got me to thinking. The fact is, I only have the 12VDC compressor on my coach. My coach is a 38' and I don't have all of the air operated systems that a lot of coaches do. The whole time I have been referring to the 110 compressor, it was actually the 12VDC that I was thinking airline was coming from (blue 3/8" airline that connects to the T at the braided hose).
AS far as my HWH system is concerned. It's actually not an HWH system. Apparently, Newell used to use HWH components and build their own. The bypass must be wired to my 12V since it comes on when the leveling system calls for air. The only air compressor switch I can find is in the cockpit area. But I think it only activates the compressor when the leveling system needs air so I just leave it on all the time.

I have sprayed bubbles (multiple times) at all of the connections touched during this process. Also used my inficon ultrasonic leak detector. Can't find anything.

Tomorrow, I am going to try and bypass the T. and connect the braided hose directly to the air dyer. I will plug the mystery 3/8" airline. I just want to see if the system will air up and hold air without this airline. Still holding out hope that maybe i damaged the check valve and that this is somehow causing the problem.

Enough rambling on. Will keep you posted.