[Richard]

Reese,

The engine air compressor feeds directly into the dryer. On the engine air compressor is a governor that sends a signal via a small air line to the dryer. That signal tells the valve on the bottom of the air dryer to "pop" or temporarily open. When it opens it exhausts any water that the dryer has collected, and it also relieves the pressure on the engine compressor. There is not a tank associated with the air dryer. It does feed the wet tank, but there is not a tank that is part of the air dryer.

The potential issue is that IF the valve is not behaving properly it may leave you with a situation where you cannot build air pressure. No air pressure means NO GO. The e brake would not release, and I think on later Newells there may even be a lock out that would prevent the tranny from going into gear.

I would definitely ask Newell about this. Your coach may be plumbed in a way that is different than what I have seen. It may be normal, and it may be a problem going somewhere to happen. I just can't say based on the info I have. Maybe some other guru with a coach of your vintage may be able to comment on their experience in providing external air.

[rcantrell52]

John and Richard,
Thank you for your responses.

Reese Cantrell
Newell Coach 1242

[Nebster]

Well, I have 1234, and I had it on shop air at Newell for months, and I never heard any hissing back at the tag, and it was all the way up to 120psi or so like you're describing, and the gauge in the very front driver compartment showed the same psi, and the gauge on the dash showed the same psi.

I don't know much about these air systems, either, except I've learned a little about how to find leaks from all the experts on this forum and from watching Newell hunt them.

Sometimes I wish Newell would actually just make a one-hour video walk-through, on every design generation of coach, that described the whole system from the top down and how it is plumbed together. None of it is that complicated (it's just air, after all), but in combination and with all the airline routing and tanks and dryers and ports, it's very hard to understand as a beginner.

They could do that one time for each coach model and save everyone a ton of time down the road, including their own service guys fielding countless phone calls from us. I don't think that would help Reese's specific problem, but this thread gave me a good excuse to rant.

[Richard]

Dang, if we could have gotten @"Chester Stone" to a rally with several generations of coaches, he could have made such a video. Chester is a fantastic documenter. But making videos like that is a great idea, and maybe something we can work on at the NonRally Rally.

[rcantrell52]

Nebster,

We were to attend the Newell rally a couple of weeks ago in Kerrville but because of the air leaks we had to cancel the trip and took the coach to Newell instead.  Part of the rally was to include a Q&A session and I had planned to ask about Newell conducting educational seminars for owners.  I planned to present my idea in a manner that the cost of attending the seminar would be incurred by the attendees, not by Newell.  So much for plans.  I feel very strongly that a structured educational program for owners because of the complicated operation of the coaches would be a very beneficial endeavor.

Thank you for your response to my question.
Reese Cantrell
Newell Coach 1242

[Nebster]

Both ideas sound great to me.

That said, from having spent a lot of time with the very knowledgeable Newell guys, they know the answers but are not natural teachers or organizers of the information they have in their brains. A good video probably would require someone else with that gift to step in and help make things thorough and clear.

I'm thirsty out here in the desert; I'll drink anything...

[rheavn]

Understanding the air system can be made easier, but it takes time & effort.  At this point I have to give credit to Richard for the idea.

Make a schematic of your air system & follow the direction of the air from the pumps.  Time & effort spent will be invaluable! It will make chasing air leaks much easier and point you in the direction of your leaks.

For those with a '99 vintage coach it has already been done and is posted in the documentation area. Asking Newell to provide documentation is not going to happen.

Just remember "no two Newells are the same", but many are similar.

[Richard]

Reese,

Start with this book. The diagram on page 6 is one that you should know by heart.
When you get your head around that, we can layer in the stuff Newell adds to it.

https://suspensionspecialists.com/techin...k_2009.pdf

[rcantrell52]

Richard,
Thank you for your phone call. I appreciate the reading suggestion and the information you provided during our conversation.

Reese Cantrell
Newell Coach 1242

[Guy]

Thanks to all of you for compressor info. It is one of the scariest areas on our classic Newell to me. I have visions of being in Odessa Texas or some similar town with a massive air leak, and no help available. The idea of the coach dropping down on the chassis, and needing a low boy to transport it is not a good one. The more i can lean about my air system, the better I feel. Richard, that Bendix document is fantastic. Knowledge is power.

I plan on replacing all four air bags just because I have no idea how old they are. My problem will be that being full timers,  I will have to have the work done, meaning i may have to pay to get the bags removed, identified, and ordered, and perhaps have the old bags re installed while waiting for replacements.