[Wanderman]

front right lower/dump is not working either.. has to be a clog...

[[email protected]]

Perhaps some crud got in the system. I would pull the solenoid body off and look for crud inside. You may have to try to use the air to blow backwards through to dislodge the crud. 

Here is a video showing the disassembly of the six packs:
https://youtu.be/MInXcfFP65Q?is=jE7IsuDhe7nTj33D

*** note it’s not good to remove the coils while they are energized, I unplugged them to make sure** it can burn out the coil if you take it off while it’s energized.

Are they making a good audible click?

[Wanderman]

Appears to be a giant chunk of crud (a piece of cut airhose) in the check valve (bottom bolt on manifold)
Removed and now It at least levels. Will check more when I get home.

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Appears to be a giant chunk of crud (a piece of cut airhose) in the check valve (bottom bolt on manifold)
Removed and now It at least levels. Will check more when I get home.

Glad you are back on the road! Safe travels!

[Richard]

Good diagnostics to take the port to the air bag loose and see what is going on.

I can’t for the life of me see how a piece of DOT tubing got into the manifold.

Some of them had a check valve where the coach air entered to raise the coach. It may have disintgrated over time.

Two other things came to mind while we were out and about.

Once, the coach would not raise. I got off the road by hotwiring the travel solenoids. The root cause was a cracked solder joint on the HWH board that fed the travel solenoids.

Second, and way more bizarre problem was that the system would go into travel or level mode, SOMETIMES. I sent the control module to HWH twice. It would come back and work for short while. I do found the root cause purely through luck. The module has five fuses at the bottom. They always tested good but while probing around with the DVM I would get voltages of 6 to 8 volts. Bottom line is the blade fuses had oxidized contact in their holders. Pulled them, deoxit, and dielectric grease. voila the wonky behavior went away never to return.

[Wanderman]

So... I am now back home. Bummer that the trip to Dayton never happened... BUT, now I know there are issues with contamination in the air system. I called HWH and after over an hour on the phone with two additional call backs, I finally spoke with someone. They had no idea that the manifold blockage could even be a thing! Of course, by that time we had found the issue.

Stopped last night to dump/fill and found that now the 120v compressor will not fill the tanks. Actually it fills the brake tanks VERY slowly and only up to about 30PSI with no indication on the supply gauge at all. The 12V compressor still fills the small tank for house systems so I still had Microphors and pocket doors. Whew!

Have to figure this out now. I'll wager its a check valve or more contamination traveled downstream to the compressor plumbing. I did notice that there are two electric air pressure valves on the manifold 20PSI? Depending on how the system is plumbed... may those are the culprit.

EVERY Newell is different.... but I'm learning. Now I can even rebuild 6 six pack valves in under and hour, upside down under the coach. I can't tell you how many times I installed and removed each one whilst troubleshooting this one!. I am ABSOLUTELY going to move the six pack to the empty compartment below the driver. No question!

[johnkosir]

On 712 there is a check valve that stops air from the 120 v tank from going to the air dryer. on 712 the air dryer is the air protection valve, air comes from the engine compressor and them gets distributed to primary supply (rear brake tank) secondary supply (front brake tank) astronic supply(?) Leveling supply, accessory supply, air chuck . 712 uses Bendex ADHS air dryer, 712 is a early ZF and still has 12 v compressor

[Richard]

Yeah, this is going to take some time.

One thing, that I would do before tearing the air system apart, is to disconnect the 120 compressor and dead head it into a gauge just to rule out a defective compressor before going any deeper. Quick, simple, and rules out one possibility.

Impossible to arm chair diagnose. One branch of logic you may want to pursue is the difference in air pressure behavior on the engine compressor vs the 120 compressor vs shop air input. The clues in that testing will help narrow the search.

Thanks for posting you are home safely, and thanks for posting what you find. It helps the next guy.