air compressor

[Robert Mathis]

My 12volt air compressor runs about every hour or so. I can't find a leak and the system very rarely adjusts the airbags. Has anyone else had a similar problem? If so, how did you fix it?

[Gerald Farris]

I am not positive how your air leveling system works, but all of the air leveling systems that I have worked on (mostly HWH) only run the 12V air compressor when two conditions are met. First the system is re-leveling and second the tank is below the the preset cut off switch pressure of about 105 PSI.

So if your 12V air compressor is running every hour or so, you have a very small air leak in the suspension somewhere. These types of leaks are usually very hard to locate, and can take a long time to find, but they are usually easily repaired. The cost is almost always in finding the leak.

It helps sometimes to let the coach set with the leveling system turned off and see which side or corner drops first. If the coach does not drop after setting a day or two, the leak is probably in the leveling system.  

Gerald        

[Robert Mathis]

Thanks, Gerald. I seldom hear the system adding air to the bags, and this happens even when the air leveling system is turned off. I'm wondering now if the air pump itself might be leaking back thru the check valve.? We have looked for a leak without success,  so my plan now is to disconnect the line out of the compressor, cap it and see if the pump runs.

[Gerald Farris]

Robert,
If the compressor runs with the leveling system turned off, you need to find out what is controlling the compressor circuit, as there is no need for the compressor to run if the leveling system is not functioning.

If it is wired to maintain pressure in a storage tank, there may be a leak in one of the connections to that tank, but if the compressor runs that much, it can run down batteries if it is stored and cause premature failure of the compressor.

It is also possible that the leveling system is activating the compressor when it should not be.

Gerald

[Robert Mathis]

It will definately run the chassis batteries down. I've had that happen several tiimes. I hope to have some time this weekend to try to get in there and unhook and plug the line to the pressure tank and see if i can find the leak.

[Gerald Farris]

Robert,
If I were you, I would check the wiring diagram for the leveling system and see if the compressor should be wired through it so that it will run only when the leveling system is turned on. That would solve a lot of your problem.

If your system has an automatic water drain at the compressor that drains when the compressor turns off like most HWH systems, it may be the check valve at it that is leaking and causing you to loose air.

Gerald

[Robert Mathis]

I actually got a little time yesterday afternoon to check the system. I found the air leak at the "T" fitting exiting the 12 volt compressor. One side of the T goes to the pressure switch, the other side to a small pressure tank/H2O seperator, all completely hidden behind the frame under the step. I removed the entire fitting, trimmed the lines and reinserted into the fitting and the leak stopped.

[Joel Ashley]

Thanks for keeping us appraised, Robert.  Air leaking back out of the tank lowered its pressure and that activated the switch to turn the pump on.  I didn't even know our small leveling system compressor might have a tank and seperator, so your info and fix, as well as Gerald's input, may come in handy in the future.  Plus it's always good to hear when someone solves a problem, and at no cost to boot  .

-Joel

[Arden Smith]

Just a thought, My air leveling system uses engine driven compressor air BUT I also was leaking air and found the air leveling control (suspension) valves by the wheels to be of a plastic body design and the plastic was cracked on the two front ones and leaking, Upon taking one of them off, the whole valve body split. Could have happened on the road with bad results. I would look around the valve bodies for a possible leak, Be careful though to tighten any connections if they are plastic because if they are cracked they may well break the body and you would have no suspension to get to the repair shop. I replaced mine with all metal body valves.

Arden Smith