[Jerry]

I have a 1996 Coach 428 and have some questions about the air system.  My coach has a Air Comp switch on the dash that turns on a compressor in the front of the coach and continues to run because the coach is releasing air in the engine battary compartment. The air release in the battary compartment releases air, even when the gauge is below 50 PSI.  There is also a compressor in  the Aquahot bay and the gauge  shows 5 PSI after setting for a week.  When driving the coach, the brake air and other air gauge go to over 100 PSI, not sure exactly, but appear to be working well.   

I will post some pictures and maybe it will help explain what's going on with the air system and how it all works together.  I would appreciate someone giving me a general overview of the Newell air system, compressors, purpose, appropriate air pressures, when air should be released, and how to adjust if necessary?  

Thanks,
Jerry

[encantotom]

hi jerry,

if you do a search on the forum you will find out alot about the air system.

that said, a few comments and questions.

there should be no time it is releasing air unless you are letting air out of the leveling system using the control panel.
where is it leaking at at when sitting still would be my first question. you need to fix that.

if it is leaking air you should see the air pressure on the dash gauge go down as well.

make sure you dont have your tag axle switch on the dash on so it is releasing air from the tag bags..... that will constantly release air.

your front air compressor will run constantly if it cannot get up to its cutoff pressure which is around 90-100psi. it will get hot and thermally shut off if let running all the time

i suspect your tag axle switch is on.

there is another switch probably over your microwave for the 12v compressor in the aquahot bay.

so check your tag axle switch first and report back

tom

[Fulltiming]

If you have not already done so, please go to http://newellgurus.com/showthread.php?tid=4957 and watch Richard's videos on the Newell Air System. You will learn an enormous amount about how your air system works.

[Jerry]

Tom,

I appreciate the help. My coach is 39 feet and does not have a tag axle. I did watch all the videos and it was very informative, didn't realize how the leveling and air brake system operated.

When I parked the coach, I released all the air from the right rear and when I turn the compressor on, that little black canister that looks like an oil filter in the picture is releasing the air. Maybe when I totally dumped the right rear, the valve is open to go down on the leveling system and that's why air is going out when the dash compressor is turned on. I read the owners manual and it tells me when using the leveling system, turn on the fast idle, raise the coach and then lower the corners that are to high. I've not done it that way and maybe I will not have to totally dump the rear wheel to level, thus stop the air being released.

It's too late tonight, so I will try it sometime tomorrow. If you have any other tips as to why the oil filter looking thing is releasing air please let me know. I'm just going to have to experiment with the coach, still don't fully understand it.

Thanks,
Jerry

[Richard]

Jerry,

Can you post some pics if what is leaking? I can’t make out what you are describing from the pictures you already posted.

Do you have an HWH panel for leveling or the Newell system which uses toggle switches for the corners?

[HoosierDaddy]

Looks to me like the “filter” could be a water trap/air filter.
The drain valve could be leaking

[Jerry]

Richard,
I think it is a filter, because it does not release air all the time. When I turn on the compressor button on the dash, brake pressure over 100 psi and the air supply pressure goes to 70. I think the air release is occurring in the filter in engine battery compartment through the filter in the picture I posted (picture is should be turned clockwise on click to make it look right). I shut off the compressor and the air supply goes to zero, the brake pressure stays over 100 and then air releasing out of the engine compartment stops. The coach does seem to hold the HWH adjustments to level and I can push the various buttons and hear it releasing or filling air. My HWH is push button with up and down arrows on front, sides and back, no toggle switch. I'm now thinking everything is okay, because maybe the air pressure with the air compressor button on is releasing air because the system is full. Maybe Great video on the air system, taught me a lot about how the HWH works and the brakes. My air pocket doors open and close, but one you have to give a little helping push. Seems like the pocket doors could use more air pressure, but I'm hearing this is a common Newell problem.

Thanks,
Jerry

[Richard]

Those air water separator filters with the clear bowls are NOTORIOUS for leaking. The polycarbonate clear piece cracks. You can either replace it or take it out.

It is NOT leaking because the system is full. The air pressure switches on the 120V and 12V compressors control the amount of pressure in the system.

One important thing to always keep in mind when chasing air leaks, when the key is off the airbags are isolated from the rest of the system by the travel solenoids. Important to remember because it helps you look for the leak. If a corner is dropping, you look at the six pack to the air bag. If the system pressure is leaking, you look at the system up to the six pack.

Get the air leak fixed first, and then see how the pocket doors perform.

Air leaks like that do a couple of expensive things. One, they burn up the 120V compressor. Two, they fill the system full of water from the compressor running incessantly.

[RussWhite]

Let me pile on a bit to Richard's suggestion to get the air leaks fixed. We could all start a list of where we found leaks, but it would end up being every place there is air. Not very helpful. As for leaks at the air filter/separator I have experienced the drain valve on the bottom of mine leaking. This happens after I have the tanks drained for some job and try to air up again. The auxiliary compressor just keeps running and then I remember, check the drain on the filter in the side engine bay access. I just push up on it and voila, it seats and no more leak!

I installed an hour meter on my auxiliary pump. One of the many mods, but one of the best. I live in my coach about 6 moths a year and set a calendar event to record the meter reading. After the replacement of the auxiliary air tank by the generator fan, by compressor time is now less than 10 minutes a day. I don't go crazy looking for leaks. It's just recycled air, but the less I leak, the longer my compressor is going to last and the less the water separator is going to have to work. YMMV

[Jerry]

I'm going to put a better picture and you can see how the air comes out of this black looking filter with holes that seem to be designed to release air.  My coach seems to hold air, my compressor does not kick on.  The air issue is when I push the compressor button on the dash and it runs the air compressor in the front of the coach without stopping.  I think the switch overrides everything and turns the front air compressor on.  The brake pressure is over 100 and then the supply air gauge goes to 70, the air starts flowing out of this black oil filter looking air release system.  Does anyone know what this air release canister is and how it should work? Please look at the picture attached.

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Sorry, old picture.  This is a better picture of the engine battary bay and view of this black air release canister.