Do air bags level coach for extended periods without running the engine?

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Do air bags level coach for extended periods without running the engine?

May 19, 2016, 08:33:56 pm

I've had my coach parked in my driveway going on two weeks plugged into AC. I went in there today and noticed the level panel was flashing red on the air icon and the compressor was running but at a lower decibel volume then I've heard before. Didn't seem to be pumping air. I went out and checked the airbags and all were deflated. Do I maybe have a bad compressor or does the engine need to be run periodically?

Re: Do air bags level coach for extended periods without running the engine?

Reply #1 – May 19, 2016, 08:42:05 pm

I level my coach and then turn the system off, and it stays level for weeks.

Re: Do air bags level coach for extended periods without running the engine?

Reply #2 – May 19, 2016, 08:49:56 pm

Goldbehen -

Welcome to the forum.

You have a bunch of questions there and I am sure that you will get lot's of places to look.

For a start you can consider these.....

Do you have air in your tanks?

Do you have an Air switch on the left panel of the Driver's seat? What position is it in - On or Off?

How long has your Aux. Comp. been running? Does it stop running, if so how long until it starts again?

When close to your Aux Comp do you hear any hissing/air loss sounds. Do you hear any hissing noises as you walk around the coach especially near the air bags?

What procedure did you use to level your Coach?

I am sure many more comments will be forthcoming.

Good luck.

Re: Do air bags level coach for extended periods without running the engine?

Reply #3 – May 19, 2016, 08:55:02 pm

My x Foretravel dealer mechanic fixed my air leaks four years ago.

Never moves after leveling and turning the coach fully off.

Re: Do air bags level coach for extended periods without running the engine?

Reply #4 – May 19, 2016, 09:02:45 pm

The procedure I follow is, I park with the engine still running. I hit the air button twice and the auto leveling does its thing. I'm on level ground so it takes less then a minute.I shut the motor off and that's it. I've been in or near it and heard it dump air and the compressor come on. Tonight the right bottom yellow light was lit,the air light was flashing red and the compressor engine was running but it didn't sound like the compressor part was kicking on. It could have been running for a while since I haven't been inside the coach for a couple days. When I was last in it all was well. so this happened over the last couple of days. I believe the air bags are original.Thanks for the quick responses.

Re: Do air bags level coach for extended periods without running the engine?

Reply #5 – May 19, 2016, 09:09:22 pm

If you have an air compressor at home you can plug a double male fitting where the air chuck is for hooking up an air hose. That way you can fill the air tanks without the engine noise and listen for leaks.

Re: Do air bags level coach for extended periods without running the engine?

Reply #6 – May 19, 2016, 09:26:38 pm

Sent you a PM.

Re: Do air bags level coach for extended periods without running the engine?

Reply #7 – May 19, 2016, 09:59:47 pm

Quote from: goldbehen – May 19, 2016, 09:02:45 pm

The procedure I follow is, I park with the engine still running. I hit the air button twice and the auto leveling does its thing. I'm on level ground so it takes less then a minute.I shut the motor off and that's it. I've been in or near it and heard it dump air and the compressor come on. Tonight the right bottom yellow light was lit,the air light was flashing red and the compressor engine was running but it didn't sound like the compressor part was kicking on.

1. The procedure you follow leaves the HWH system in "Auto Level" mode. That is fine - no problem.
2. One corner (or side, or end) of your coach is "sagging" while parked, due to a leak (or leaks) somewhere in the system.
3. In "Auto Level" mode, every 30 minutes, the leveling system checks the status of the coach.
4. If one corner (or side, or end) is low, the system attempts to correct by releasing air from the opposite corner (or side, or end). This is the "dumping" sound you hear.
5. When the coach reaches a position where the system cannot achieve level by releasing air, it will attempt to add air.
6. The system tries to add air by running the aux air compressor. This is why you hear the compressor motor running.
7. If running the compressor does not cause the coach to achieve level, the red "AIR" light should start flashing, and the "EXCESS SLOPE" light should be on, in addition to one or two yellow "Level Sensing" lights.
8. The aux compressor will continue to run, trying to achieve a level condition, until it either succeeds, or you turn the system off.
9. If the aux compressor is running, but cannot build pressure, then you have another leak. Most likely suspect is the pressure release solenoid on the bottom of the air dryer canister, which is attached to the aux compressor. This is a NO (normally open) valve which should close when the compressor is running. If it is stuck open (very common), then the compressor cannot build pressure.
10. First, fix the leak at the aux compressor, then the system will be able to keep the coach level, and it will be happy.
11. Then, figure out what is causing one corner (or side, or end) to drop, and fix that. Then you will be happy.

http://www.hwhcorp.com/ml11148.pdf

http://www.hwhcorp.com/ml20635.pdf

Technical Help - HWH

Re: Do air bags level coach for extended periods without running the engine?

Reply #8 – May 19, 2016, 10:26:39 pm

Just finished a conversation with Scott who gave me some good direction. Tomorrow I'll start the diagnostic process and see what I come up with. In the meantime I can't say enough about how valuable this site has been. Thanks again!

Andy

Re: Do air bags level coach for extended periods without running the engine?

Reply #9 – May 19, 2016, 10:36:01 pm

Just spent some time on the phone chatting with godbehen and discussed many of the things that Chuck and Jeannie wrote, although they wrote it much better than I spoke.

His coach was sitting in his driveway plugged in and lost air pressure in his air bags and his aux. comp turned on as well as lights on his HWH control panel.

When he gets an opportunity in the next day or two he will energize his leveling system, wait for the Aux. Comp. to start and start listening/feeling for leaks starting with the aux. compressor itself then move on to the air bags. If the Aux. Comp. does not inflate the air bags soon I asked him to start his engine so the engine air compressor would start and fill the air tank in the front of his coach. I did advise that his aux. comp. produces much less air volume than his engine compressor. Once air has filled his tank then sit the engine off and again listen/feel for leaks.

He said he would report back.

I couldn't help but remembering how helpless I felt when confronted with my first few coach issues.

We do have a great group here.

Re: Do air bags level coach for extended periods without running the engine?

Reply #10 – May 19, 2016, 10:41:29 pm

That compressor should only run a very short time. Continuos running will burn them out. Leaks are the cause, and I have burnt up a couple before I realized that was the issue. MOT just finished a search mission over three days finding most of my leaks. Compressor comes on very occasionally and runs maybe 30 seconds and shuts off.
If it changed sound is is probably toast from over heating.
Others smarter than I on what the pump inflates can chime in, but that was my experience. Googled the part number and manufacturer, and bought them for about $250 each. The company also makes a rebuild kit for about half the cost of the pump.

Re: Do air bags level coach for extended periods without running the engine?

Reply #11 – May 19, 2016, 10:42:43 pm

FWIW, Keith Risch at MOT says most of the leaks, if big ones seem to be connections close to the pump. Maybe vibrations?

Re: Do air bags level coach for extended periods without running the engine?

Reply #12 – May 20, 2016, 03:06:30 pm

I have found the 12 volt air compressors do not provide enough volume, so I replaced mine with a 120VAC air compressor. AC power is provided by the inverter when boon docking or shore power via a duplex receptacle near the air compressor. I installed a 12v dc /120VAC solenoid which provides AC power to compressor when the HWH demands air (same as with 12v compressor). Now the volume of air supplied is almost ten times higher and the compressor cost is about $125 (half what a good 12v compressor costs). I also installed a manual switch and use this compressor for filling tires.

Re: Do air bags level coach for extended periods without running the engine?

Reply #13 – May 20, 2016, 05:19:12 pm

Quote from: P. Wyatt Sabourin – May 20, 2016, 03:06:30 pm

I have found the 12 volt air compressors do not provide enough volume, so I replaced mine with a 120VAC air compressor. AC power is provided by the inverter when boon docking or shore power via a duplex receptacle near the air compressor. I installed a 12v dc /120VAC solenoid which provides AC power to compressor when the HWH demands air (same as with 12v compressor). Now the volume of air supplied is almost ten times higher and the compressor cost is about $125 (half what a good 12v compressor costs). I also installed a manual switch and use this compressor for filling tires.

Couple of questions Wyatt;

Is this the type compressor? Portable Tire Ball Pool Toys Infiltrator 120V Car Bikes Flat Air Pump...

Did you plumb the solenoid valve into the already existent pressure switch?

Re: Do air bags level coach for extended periods without running the engine?

Reply #14 – May 20, 2016, 09:52:32 pm

Well I started the engine to fill the air tanks and inflate the air bags to travel height. Since we'll be away over the weekend without the coach I want to see if it holds air without the auto leveler engaged. Walking around and listening at all the wheel wells I didn't hear any air leaking. My compressor is located behind the inverter and not easy to get to. When I get back, if there's no sign of leaking, I'll try the auto level and see if the compressors working. I did see a glass cylinder on the bottom of the compressor. Didn't see anything in the bottom.looked like an empty bell jar. I guess I'll have to crawl in from the other side to get access and a better look.

Re: Do air bags level coach for extended periods without running the engine?

Reply #15 – May 20, 2016, 09:58:26 pm

Quote from: P. Wyatt Sabourin – May 20, 2016, 03:06:30 pm

I have found the 12 volt air compressors do not provide enough volume, so I replaced mine with a 120VAC air compressor. AC power is provided by the inverter when boon docking or shore power via a duplex receptacle near the air compressor. I installed a 12v dc /120VAC solenoid which provides AC power to compressor when the HWH demands air (same as with 12v compressor). Now the volume of air supplied is almost ten times higher and the compressor cost is about $125 (half what a good 12v compressor costs). I also installed a manual switch and use this compressor for filling tires.

If memory serves me the older unihomes came with 110 volt compressors. But no where near the battery and inverter capacity.

My 12 volt only comes on with an up signal from the hwh panel.

Do you have an air dryer in that circuit.,...

Re: Do air bags level coach for extended periods without running the engine?

Reply #16 – May 20, 2016, 10:55:57 pm

This topic brings me to think I have never had that compressor since owning the coach in auto level as this coach stays for weeks as I leave it!
I do know the compressor works as the odd time I have to do a slight manual change and can hear it run but as all say it does take a while to make much change in leveling,but hey, what's the rush??
JohnH

Re: Do air bags level coach for extended periods without running the engine?

Reply #17 – May 20, 2016, 11:04:39 pm

You might consider pulling the fuse for the compressor so if it starts while you are gone and doesn't stop it will not over heat and destroy its self. There should be an inline fuse on the 12 volt power wire going to the aux comp - red or black wire and the fuse holder is probably about the size of a square 1/2 dollar. The fuse is an automotive type with two spades. The cap will pull off then you can pull the fuse. FWIW

Aux compressor fuse, fridge not cooling on propane when underway

A drawing of the compressor assembly is in the above link.

That clear glass bowl is probably where desiccant material goes, but can't be sure with out a pic. The desiccant material is supposed to keep moisture out of the air system produced by the Aux Comp. There is also a solenoid that "pops" when the aux comp shuts off and relieves pressure in that side of the system and is mounted on the bottom of the glass bell bowl.

My guess is that some kind soul on the forum will correct any mis statement I have made.

Have a great weekend.

John H. - You are my hero. Wish my system was as tight as yours.

Re: Do air bags level coach for extended periods without running the engine?

Reply #18 – May 20, 2016, 11:16:04 pm

Agree that compressor will self destruct, ask me how I know......

Simple solution is to cut the red wire where it is very accessible. When you go back, bring some crimp on terminals - I put a male/female spade type in mine, came in handy when I replaced the compressor from failure due to overheating.....

I also plumbed a inexpensive air gauge into the system so I could easily see air pressure, cut in and cut out pressures

Re: Do air bags level coach for extended periods without running the engine?

Reply #19 – May 21, 2016, 01:43:40 am

The original aux compressor seemed anemic to me. When I was stranded by the side of the highway in Canada awhile back, no amount of running the aux compressor would raise up the rear. I was forced to work with almost zero clearance to do the air dryer bypass out of improvised parts. I have since replaced the aux compressor with an ARB twin compressor system that will fairly quickly raise the whole coach high enough to block the frame with 12" square tubes. It is 12V, but not cheap. I am okay with that...
Don

Quote from: P. Wyatt Sabourin – May 20, 2016, 03:06:30 pm

I have found the 12 volt air compressors do not provide enough volume, so I replaced mine with a 120VAC air compressor. AC power is provided by the inverter when boon docking or shore power via a duplex receptacle near the air compressor. I installed a 12v dc /120VAC solenoid which provides AC power to compressor when the HWH demands air (same as with 12v compressor). Now the volume of air supplied is almost ten times higher and the compressor cost is about $125 (half what a good 12v compressor costs). I also installed a manual switch and use this compressor for filling tires.

Re: Do air bags level coach for extended periods without running the engine?

Reply #20 – May 21, 2016, 09:22:30 am

Quote from: Don & Tys (AKA acousticart) – May 21, 2016, 01:43:40 am

The original aux compressor seemed anemic to me. When I was stranded by the side of the highway in Canada awhile back, no amount of running the aux compressor would raise up the rear. I was forced to work with almost zero clearance to do the air dryer bypass out of improvised parts. I have since replaced the aux compressor with an ARB twin compressor system that will fairly quickly raise the whole coach high enough to block the frame with 12" square tubes. It is 12V, but not cheap. I am okay with that...
Don

Doesn't the engine compressor make enough air to raise the coach to put the blocks in?

Re: Do air bags level coach for extended periods without running the engine?

Reply #21 – May 21, 2016, 09:30:43 am

Quote from: craneman – May 21, 2016, 09:22:30 am

Doesn't the engine compressor make enough air to raise the coach to put the blocks in?

Don had complete loss of system air pressure due to air dryer malfunction.

Re: Do air bags level coach for extended periods without running the engine?

Reply #22 – May 21, 2016, 09:42:04 am

Quote from: Chuck & Jeannie – May 21, 2016, 09:30:43 am

Don had complete loss of system air pressure due to air dryer malfunction.

Does the auxiliary air compressor bypass the air system of the coach? I wondered why there was a portable air compressor in one of the storage bays when I bought my Foretravel, seemed a waste so I stored it in my shop.

Re: Do air bags level coach for extended periods without running the engine?

Reply #23 – May 21, 2016, 09:48:57 am

You use their aux air to keep up the level system on your coach. It runs very seldom but on a coach with slides it us used to inflate and deflate the bladders.

Re: Do air bags level coach for extended periods without running the engine?

Reply #24 – May 21, 2016, 09:55:52 am

lots of ARB compressors out there

Google

which one did you get?

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