Author Topic: Aux. Air Pump  (Read 9132 times)

Dennis Crawford

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Aux. Air Pump
« on: January 19, 2010, 06:46:03 PM »
To All:

I have a 2005 Monterey with air leveling.  I never hear the aux air pump come on and I know I am low on air (another issue with an air leak somewhere).  But this pump should come on and pump up to the proper pressure and I never hear it.  Is there an easy way to see if the pump even works?  

Thanks,

Dennis

Gerald Farris

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Re: Aux. Air Pump
« Reply #1 on: January 20, 2010, 12:51:42 AM »
The best way to check the leveling system electrical air compressor is to run a fused 12V positive wire to the hot terminal and a good ground to the ground terminal. This will cause the compressor to run if it is good.

From your question, it sounds like you think that the electrical compressor should keep the air tanks aired up at any time that the leveling system is turned on. That is not the way that most systems work. In most systems the compressor is turned on only when the system needs to increase the air pressure in one or more of the air bags and the air pressure in the tanks is below the predetermined set point.

Gerald  
« Last Edit: January 20, 2010, 08:17:00 PM by 14 »

Joel Ashley

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Re: Aux. Air Pump
« Reply #2 on: January 20, 2010, 09:37:11 PM »
Our '06 Monterey has always had a microleak somewhere in the left rear bag system, and the compressor commonly takes over when we are camped and tank pressure is diminished, as Gerald points out.  

Another option, if you don't have a handy-dandy portable power/jump start/compressor unit to tap 12 v. from for example, or some other convenient 12v. source, is to jump across the pump's hot and ground studs with an ohm meter.  Disconnecting the hot lead would be a good idea first so you can't harm the meter if the leveler panel sends juice to the pump during your test.  There should be some resistance (ohms) there if the pump motor is okay.  Most commonly available voltmeters have the ability to measure resistance, or continuity.  Continuity means wiring is intact from point A to point B in a circuit, such as within your pump motor, and electric current can flow through it from battery to chassis ground unimpeded by a short, open switch, loose connection, or broken wire.  Most meters have a simple test option for continuity with an audible continuous sound if a tested circuit is intact and okay.  The voltmeter's onboard battery sends a low-voltage shot through one lead;  if it goes through the tested circuit and makes it back through the meter's other lead, then you hear the sound and all is well.  Theoretically.

If your pump's motor circuit tests okay, then the problem is likely upstream at a fuse or connection or perhaps a relay between the pump and the air system control unit, or perhaps a bad ground connection from pump to chassis.  Check your wiring diagram book to follow leads.
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat

Tim Bentley

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Re: Aux. Air Pump
« Reply #3 on: January 21, 2010, 07:37:18 PM »
I have on 03 Marquis with air leveling.  When the system needs air I can hear the pump come on and it may rum for 15 to 30 minutes before the leveling is complete.  Would it be possible to replace the current pump with one that puts out more air?  I have looked on line and cannot find a pump to make the replacement.  Does anyone know what type of air pump this is and where I might get a replacement with more capacity?

Tim

George Harwell

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Re: Aux. Air Pump
« Reply #4 on: January 21, 2010, 08:55:47 PM »


Don't know if this will help but try HWH corp. in Moscow Iowa. They installed my system and the pump rarely turns on. 800-321-3494
Also be advised that the pump takes much longer to level the rear due to the increased weight.

Gerald Farris

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Re: Aux. Air Pump
« Reply #5 on: January 22, 2010, 04:25:49 AM »
HWH uses two basic 12 volt compressors. They are both Thomas compressors. One has a larger air flow capability than the other. The smaller compressor develops .43 cfm at 60 psi and .27 cfm at 100 psi. The pressure relief for the smaller compressor is normally set at about 110 to 115 psi. The larger compressor develops .95 cfm at 100 psi and .70 cfm at 140 psi. The relief for the larger compressor may be set as high as 140 psi.

My 2000 Marquis was equipped with the smaller compressor that failed when the coach was about 5 years old. I replaced it with a Viair 380C compressor that pumps air 3 times faster (.81 at 100PSI) and has a 100% duty cycle at 100PSI. To run the higher output compressor you will need to add a high amperage relay in the circuit.

If you have the larger compressor and want higher output, you will need to add a second compressor as you can also do with the smaller one if you want to keep it and add a second compressor.

Gerald

William Mathews

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Re: Aux. Air Pump
« Reply #6 on: January 22, 2010, 05:20:14 PM »
Do those air bag leveling compressors add air thru the regular system dryer or have some sort of dryer of their own?

Tim Bentley

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Re: Aux. Air Pump
« Reply #7 on: January 22, 2010, 06:35:25 PM »
Thank you Gerald

I found several sources for the air pumps on the internet using the description you provided.

Joel Ashley

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Re: Aux. Air Pump
« Reply #8 on: January 22, 2010, 08:55:44 PM »
I understand that Viair is a very good brand of compressor, albeit not cheap.  You get what you pay for.  Their website, http://viaircorp.com/OffRoad/compressors.html, may offer you some options.
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat

Gerald Farris

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Re: Aux. Air Pump
« Reply #9 on: January 23, 2010, 04:18:10 AM »
The auxiliary (air leveling system) compressor does not pump air through the engine air dryer, but it has a small water separator (in most applications) that dumps any water that it collects when the compressor cycles off.

Gerald