Power Gear Leveling System Air Pump

[Jerry Jayne]

My 2009 Beaver Contessa has just developed an issue with the Power Gear Leveling System's Air Compressor "activation swith".  The pressure swith for the "auxilliary air tank" seems to be sensing it needs more air, and it cycles the air pump on but then turns it off about 1/2 a second later.  This cycling (I call it 'burping') is continuous 24 hours per day.  It's happening every 30 to 60 seconds.  I dont know if the problem is the tank really needing some pressurization and the switch is "inadvertently" shutting the pump off after it has run for 1/2 second - or if the tank DOESNT need any more air pressure and the swith is "inadvertently" turning the pump ON (only to have it sence sufficient pressure and shut the pump off within 1/2 second).
If I manually drain air out of the tank (like to expell water) the pump will cycle on like it is supposed to and continue operating for quite some period - like maybe 15 or 20 minutes to recharge the air tank.  Then it goes into this cycling stage of "turn on/immediately off" (kind of like a burp) every 30 to 60 seconds.   It did not do this when it was new.  When new, it would wait until sufficient air had been used out of the tank, then the pump would cycle on for a period of time to "re charge" the tank ... then the pump would turn off and stay off until it was time to "charge" up again - maybe a day or so later.  
I found the thread(s) where people had issues with the air pump running continuously ... and saw the references to air leaks in the system causing the air pressure to drop but I dont think that is my problem.  
Or is it?  What is wrong?  Should some part be replaced? Should I look for leaks?
Jerry Jayne (fairly new BAC member)

[LEAH DRAPER]

I would suspect air leaks.  I took my coach to Beaver Coach in Bend, Oregon and they found 7 air leaks.  Not sure all of these had to do with the Power Gear leveling but when they were through I had no more problems with air bags or the leveling system and they re-set the leveling system to the base level that is necessary for it to properly sense what it needs to do to level when parked and activated.  Don't know where you are located, but these guys sure know what they are doing.  They are the best.

[Jerry Jayne]

It seems to me the sensor that turns the air pump ON and OFF should have some sort of ability to let the air tank drain down to some predetermined level, BEFORE it activates the pump to charge up the tank again.  What I'm getting is: every 30 seconds or so the switch turns the pump on ... but then the pump turns off immediately (a 1/2 second "burp").  If this were caused by air leaks, shouldn't it wait until the air tank drains down to some predetermined level ... then turn the pump ON for some duration to refill the tank?  It wouldn't cycle on/off,  on/off, on/off so often ... would it?  I'm feeling the problem is more likely in the pressure sensing and pump activation mechanisms than in air leaks in the "plumbing".   But I'm a long way from Bend, OR and I don't know who has the talents to KNOW what is wrong and quickly fix it.

Power Gear has NO customer support at all.  I've sent them an email, we'll just have to wait to see if they respond.
Jerry

[LEAH DRAPER]

JERRY
What you are saying makes sense and if set up properly that is what mine does.  Am sorry I can't be more specfically technical, but before my leaks got fixed my pump came on somewhat frequently, but not as you describe yours is.  I would give a call to Bend Service center and talk with Loren (service advisor) who can perhaps talk to one of his techs more familiar with the system if he can't answer your questions.  His number is: 1 541/317-3669.
 
As you probably already know, the system initially levels the coach then goes to "sleep" and wakes I think every twenty minutes to see if the coach is still level, if not level it will let air out of the offending side or turn on the pump to fill air.  Have you followed the Power Gear instructions for setting it up?  (I trust you have), but thought I'd mention it anyway.  

[Jerry Jayne]

Yep, set up the coach per the instructions.  Its not that it's getting off level (I can hear the air valves open and close when its off level) ... its that the air pump for the air resevoir runs every 30 to 60 seconds for 1/2 second.

I got under the coach yesterday and looked everything over.  The Air pressure sensor (switch) has a label on it that says "ON at 90 PSI" and "OFF at 120 PSI".   Makes all the sence in the world.  When the auxilliary tank gets down to 90 psi the pump goes on to fill it back up to 120 psi.  Then it turns off.

But mine seems to think its below 90 psi ... turns the pump ON ... then thinks its up to 120 psi 1/2 second later ... and turns the pump OFF.   Probably a swith (sensor) failure.

But I also found a 12V HOT wire to the pump that had obviously overheated and had almost melted the plastic connector going to the motor of the pump.  Wire was black, and plastic connector was brittle and broke immediately when I disconnected it.  No 20 A fuse had blown ... just a wire showing heat distress.  Hummmmmm.  What does that indicate???

I sprayed soapy water over everything and found  some bubbles around the connector where the pressure sensor is piped in ... but  with some wiggling it went away and I could NOT make it come back - no matter how much I tried!  So I cant reproduce the Leak I found once.  
Boy, lots of wierd things now.

And here's the latest wierd thing.  After wiggling lots of things around the pump & switch and thightening up what I think is the intake filter for the air input to the pump ... and filing/sanding off the black soot on the electrical connection that had developed on the 12V lead to the pump ... the problem went away overnight.  No more "burping".   But it came back the next morning when I drained the air tank down to make sure I really still had 12V power to the pump.  So I've been able to make it stop, but dont know how specifically.  Wierd!  I obviously changed  something.  But What?

Thanks for your thoughts, I'll just have to see from here on if I can reproduce the symptoms.  Will Call Bend Service Center to see if they can help diagnose the problem.  Thanks again.

Jerry

[Robert Mathis]

Jerry, it sounds like to me that your pressure switch is bad. There is a small possibility that the tiny leak you found might have ben causing the problem, but it's doubtful. You can get a replacement switch at almost any supply shop that handles air and hydraulic fittings. If your coach is like mine, the air hoses are connected with a self sealing type connector. One pushes in on the end, and the connector releases, then when you put the hose back in, it automatically grabs the hose and seals. I would suggest getting a pressure switch, replacing it and the nearby connectors and see what happens.

[Wayne Tull]

Jerry,

The 12v. connector being burnt will happen most any time you don't have a good mechanical connection on a high current draw connector.  The poor connection leads to some amount of resistance which turns the connection into a miniature heater.  Over time it just gets progressively worse.  

Unless there is a relay to check between the pressure sensor and the pump, my vote is for the sensor.

[Gil_Johnson]

I had this exact problem, cycling on an off every minute or less.  It's natural to suspect the sensor given there's no way it should cycle so often given its parameters.  If not mistaken it should turn on at 90psi and off at 120psi.  The problem with my 2008 Contessa is that the sensor switch was installed in the wrong place.  There's an air line that comes off the air tank leading to the small air compressor.  In that line there should be a check valve.  My check valve was located at the tank, the logical place for it to be.  My pressure sensor switch was located on the same line at the air compressor.  Air compressor pumps will naturally leak down and that's why the check valve is installed at the tank on the line to the air compressor.  In my case and it sounds like yours as well, the small amount of air contained in the line after the check valve and in the air compressor can quickly leak down signalling the compressor to come on.  It will not run long because it only needs to refill the small air hose assuming your coach's air system is not leaking.  I moved the air pressure sensor switch to the other side of the check value and that problem was cured.

Gil
08 Contessa

[Jerry Jayne]

Wow, love the support you all are giving.  

1) I will try to find out how to "Move" the pressure switch to the output side of the air tank so it is NO longer on the air compressor (input) side of the air tank (which from inspection I can confirm ... thats where it is).  Dumb, Hugh!

2)  After that move, if the problem still exists, I'll install a new sensor/switch.

3)  Thanks for the "reminder" that 12V connectors can/will overheat without good mechanical connection.  I'll have to re-inspect now that I've cleaned it and see if its still overheating.

Jerry

[Jerry Jayne]

To finalize this posting:  I found and fixed the problem.  Here's the solution (for anyone else that experiences this problem).  Beaver installed an "extra" (unneeded) check valve at the air tank.  Just replace it with a normal 1/4" air hose connector (and throw away the installed connector that has a "Check Valve" imbedded in it.  Got this info from VALID MFG 250-832-6477.  They're the people who took back the air leveling manufacturing from Power Gear (they originally had it anyway).  Very knowledgable folks.  Told me their compressor for the air tank already has a check valve in it to keep from losing air back thru the pump.  But the one Beaver (Monaco) installed at the air tank causes the problem.  It causes the short air line ( < 12") from the compressor (air pump) to the air tank to not hold and register the pressure that is in the tank ... and if and when a miniscule air leak develops ... that short line it will not stay pressurized and will cause the pump to cycle on/off way too frequently (because that line is the one with the air pressure sensor on it).  I got part KQ2H07-35S from Coast Pneumatics 714-921-2255 for under $3 (plus shipping).  It is a straight quick connect connector for 1/4" air hose on one side, and  1/4" NPT threds on the other.  Just unscrew the current connector which has a check valve built into it (just press in on the tab on the connector, and pull the air line out ... its a quick disconnect).  Replace that connector with the "Normal" connector (listed above) and push the air hose into its quick connect ... and the job is done.  No more needless cycling of the air pump.  (PS thanks Gill, you had it right).

[LEAH DRAPER]

Good news

 " VALID MFG 250-832-6477.  They're the people who took back the air leveling manufacturing from Power Gear (they originally had it anyway).  Very knowledgable folks.  "

One could never get them to respond to emails anyway and they would not publish a phone number on their web either.

Hope things will be better now.

[Steven Link]

Wow, Thanks Jerry and Gil, I have been having this exact same problem but could not find any leaks. Guess the PG leveling that Beaver used in late '08 are all starting to fail at the same time. I will try replacing the connector and see what happens.
Thank you for making my wife happy...she is growing tired of hearing the constant compressor burp!

[Gil_Johnson]

Steve,

Simply disconnect the pump until you can get around to fixing it.  I found that I could sit for a good week without any change in leveling with the pump off.  If you do this, turn off the auto leveling system after it's level.  Otherwise, the auto system might make some miinor adjustments that bleeds down the air supply sooner.

Gil

[Ron Langdon]

Hey, guys, thanks for the information on the Power Leveling System. Have not had it yet, but mine is a 2008 Patriot Thunder. Listed the phone number and the fix directions in my binder.

[Kirk Foster]

Resurrecting an old thread, but it may be worthwhile to someone in the future.  I experienced this problem recently.  A check of the plumbing of my system showed that the pressure sensor switch was properly installed between the tank and the one-way valve.  I noticed that I could triggger the "burp" by grabbing the top of the switch and jiggling it, and I deduced that the switch had failed.  Called Valid, and they said the replacement switch is about $50 plus shipping.  Found a switch from a company on ebay called Hornblasters (http://www.hornblasters.com/) that does the same thing (12/24v, 90-120 psi, 1/8" mip connector and two spade terminals) and got it for about $16, shipped.  It fixed my problem.