Aux pump running too much Was: What does this mean?

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Aux pump running too much Was: What does this mean?

February 28, 2016, 09:38:08 am

For the past couple of weeks we've noticed that the 12v air compressor has been running quite a bit. It runs for several minutes at a time, then stops with a bang. Some time later it repeats. Prior to this we would go months without it running. Right now we're sitting on the right tires and the left side is above the tires an inch or two.

I just checked the level, and it shows level on a couple places on the kitchen counter, at the rear door of the bathroom, and one of two places on the bathroom counter. The rear bathroom door opens by itself, and this afternoon I'll check the door itself to see if it is out of adjustment.

Re: What does this mean?

Reply #1 – February 28, 2016, 10:54:05 am

Is your HWH panel ON or OFF? If ON, what lights are showing? Did the panel indicate you were "level" when you last parked and shut down the engine? Need more data...

Re: What does this mean?

Reply #2 – February 28, 2016, 01:47:25 pm

We're parked, HWH is/was leveled, it is now showing that the tail is low and has excessive slope. We're actually level.

Re: What does this mean?

Reply #3 – February 28, 2016, 02:02:25 pm

probably your spider level gauge for showing level or not if you are. The 12 volt running is a leak somewhere.

Re: What does this mean?

Reply #4 – February 28, 2016, 02:16:49 pm

Dave,
If the coach is level but now the HWH panel shows out of level that sounds like a level sensor problem. Something easy I would check the cable connection on the sensor and at the computer .
Then just to check the overall health of the system you could start the engine, raise the coach full up,then level it up high with all corners off the hard stops, then turn off the system and measure the airbags and wait and measure to see what if anything changes. If it changes
you will know where to start looking for a leak.
JD

Re: What does this mean?

Reply #5 – February 28, 2016, 02:33:00 pm

Thanks for the suggestions. I'll check some this afternoon and can see what happens with leveling tomorrow when we land in Corpus Christi.

I just love checking for leaks.

Re: What does this mean?

Reply #6 – February 28, 2016, 05:02:13 pm

Give it time. Patience. It may be nothing. If this keeps recurring every time you park and level, then troubleshoot.

Re: Aux pump running too much Was: What does this mean?

Reply #7 – February 28, 2016, 10:25:23 pm

I turned the HWH system off before we went to church for the chili cookoff this evening. The aux pump was running at that moment, and it immediately shut off. That was over five hours ago, and we're still level. Tomorrow we move to Corpus Christi, and I'll level then and see what happens.

Re: Aux pump running too much Was: What does this mean?

Reply #8 – February 29, 2016, 10:17:40 am

In the previous response that says - the aux. pump running means there is a leak -
The leak is in the leveling system as opposed to the air system in general, correct?

Re: Aux pump running too much Was: What does this mean?

Reply #9 – February 29, 2016, 01:15:12 pm

Correct

Re: Aux pump running too much Was: What does this mean?

Reply #10 – February 29, 2016, 02:16:32 pm

From David's description, it sounds to me like he has two problems.

First, the HWH computer "thinks" the coach is not level, when it actually is. This erroneous indication could be caused by something as simple as the level sensor getting slightly out of adjustment. If that is the problem, it is easy to correct.

Second, the HWH aux pump is running, but not accomplishing anything. If the HWH panel is left "ON" after the coach is leveled and parked, it will go into "Sleep" mode. In this mode, it wakes up every 30 minutes and looks at the level indicators on the HWH panel. If the panel shows a "out of level" status (one or two yellow lights on), then the computer will try to correct this condition. If there is insufficient pressure in the air tanks, the 12 volt aux compressor will run. Since David's compressor is running, but having no effect on the stance of the coach, it sounds like the compressor output is escaping through a leak. When this happens, the compressor controller will "time out" and eventually shut off. Then, 30 minutes later, the cycle will repeat.

To find the air leak, I would start by looking at the compressor itself, the water filter/separator (if one is fitted), and the attendant air manifold connections. It is not uncommon to find leaks in this area.

Re: Aux pump running too much Was: What does this mean?

Reply #11 – February 29, 2016, 03:07:15 pm

The reason I asked the question about the source of the leak is because I have a similar problem.
I recently had a rapid drop in the front driver area while leveled. I had it checked and was told that I had a leaking air bag and solenoid in that area. Both were replaced and the front is working normally again.
However my coach loses all air pressure after 6-8 hrs of parking. This has been going on for some time. So when the LEVELING system was addressed, I had them check for other leaks also. They said that they found and fixed about 10 leaks in the AIR system.
The process took about 2 days and cost 2 coach bucks.
Well now, I still lose all the air pressure in about 10 hrs.
My aux compressor is running a lot also whereas before this problem started, although I would lose all air pressure, I would remain level and the aux compressor would not run.
So if I am reading the previous explanations correctly, my current situation suggests that I still have a leak somewhere in the leveling system - correct?

Re: Aux pump running too much Was: What does this mean?

Reply #12 – February 29, 2016, 05:22:21 pm

I'm interested too. My 12V Aux Compressor turns on every 11 minutes that is much shorter than 30 minutes sleep mode. I got no hissing sound anywhere. Where should I begin?
Thanks,
Michael

Re: Aux pump running too much Was: What does this mean?

Reply #13 – February 29, 2016, 07:30:32 pm

Kearn,

As you have found out, chasing air leaks can be...challenging. I am also currently engaged in that pursuit, so I sympathize with you and David.

I don't know where your leaks are - I don't even know where MY leaks are. All I can suggest is that you take a systematic approach to your search. If you know what leaks were "fixed" by your previous service appointment, that might help eliminate some possibilities (assuming they really were fixed). You need to study the air system diagram for your coach (you DO have a schematic, don't you?). AND, you should study the operator's manual for your HWH system until you have a good understanding of "where the air goes". After that, plan to spend a lot of time on your back under the coach, spraying soap solution on fittings.

HWH Operators Manuals for Foretravel

Let's consider your "compressor running inappropriately" problem. Since David also has this same problem, we are not straying too far from his original question. On our old GV models, the aux compressor only runs when it is told to by the HWH computer. We do not have a manual ON-OFF switch, like some of the newer models (at least I don't). The HWH computer only calls for the compressor to run when it THINKS the coach is NOT level. In that case, it sends a "run" signal to the compressor, but the compressor will still not run unless it sees low pressure in the line it uses to feed the air manifolds,,,usually 105 P.S.I. or less. Once the pressure in the air system exceeds 115 P.S.I., the compressor should stop running.

Ideally, when you level your coach, it should stay level. There are check valves in the 6-pack manifolds that are supposed to hold the air in the bags, regardless of what pressure is in the air tanks. You can see this for yourself...simply level your coach and then drain all the pressure out of all 3 air tanks using the water drain valves. The air bags should remain inflated, and the coach should remain level, for a long time. If they do not, then you have a leak - in a bag, or the hose supplying a bag, or the check valves in one of the 6-pack manifolds.

So, what you need to figure out is two things (same as David): Why is the HWH computer telling the aux compressor to run, and where is the air going when it DOES run. Like I recommended in the post above, I would start at the compressor, looking for leaks. The air dryer on the compressor has a automatic valve on the bottom that closes when the pump runs, and opens when the compressor turns off. I had a major leak there when we bought our coach. The desiccant had self-destructed and fell down into the valve, blocking it open. My compressor would run forever and never build pressure. Replacing the dryer desiccant and cleaning out the valve cured the problem. If everything on and around the compressor looks good there, then keep following the air diagram. On my coach, the aux compressor feeds into the line that supplies:

1. The front 6-pack
2. The rear 6-pack
3. The cruise control system
4. The air step (many members have found leaks in the step actuators)

I have elected to hunt my leaks by first rebuilding the 6-packs. Once I know they are in good shape, I have eliminated several potential "leak points". If that doesn't solve my problem, I'll keep looking at the next likely suspect.

Good luck!

Re: Aux pump running too much Was: What does this mean?

Reply #14 – February 29, 2016, 07:38:51 pm

Chuck,
Thanks for the detailed response. My Aux compressor does restore a level position then turns off. So I must assume that I have a new leak (or a previous leak that was not fixed) in the leveling system.
Thanks again for the explanation.
Kearn

Re: Aux pump running too much Was: What does this mean?

Reply #15 – February 29, 2016, 10:10:58 pm

Well, we made it to Corpus Christi this afternoon. Instead of just leveling, I dumped the air first and then leveled. (I wonder why I didn't think of doing that long ago, since it puts the step much closer to the ground.) We're level, and the aux compressor hasn't kicked in at all. Of course, there is still air in the tanks, so maybe it will come on during the night or tomorrow. We'll see.

Chasing a leak that isn't there just adds to the fun.

Re: Aux pump running too much Was: What does this mean?

Reply #16 – February 29, 2016, 11:16:47 pm

Kearn, on your way home stop at HWH in Iowa. They are about 50 miles west of the Illinois border on I80.

Nice COE campground near DesMoines and a great one just south of I80 on the Mississippi River on the Illinois side.

HWH says they are in Moscow but they are actually just off I80. Call 2-3 weeks ahead of time and you can get an appointment. Arrive the day before and they have 50 amp hookups. You can't get into their place on Sundays so Tuesday or Wednesday appts are good. If there is anything that is going to take any extra time the weekend won't be an issue. They will put your coach up on the big rack and check everything. They will flag everything that is leaking, show you where they are and fix any parts that are part of their systems.

It is cheap (a leak check is about $50)! It is something we have done just about every time we have been anywhere near.

Roger

Re: Aux pump running too much Was: What does this mean?

Reply #17 – March 01, 2016, 11:11:58 am

Coach is still level, air gauges show about 65 pounds, compressor isn't running. I've done nothing.

X2 on visiting HWH. We actually spent the night in our coach while it was up on that big yellow rack. Interesting experience.

Re: Aux pump running too much Was: What does this mean?

Reply #18 – March 01, 2016, 11:40:06 am

Dave,
In reply #7 you say the pump was running when you turned the system off but five hours later the coach was still level. If the coach was level why was the plump running?
I think when the last out of level lite goes out the pump will turn off.
Is there a disagreement on when the HWH system sees level and what you measure on say the kitchen counter?
JD

Re: Aux pump running too much Was: What does this mean?

Reply #19 – March 01, 2016, 11:47:23 am

Roger,
Thanks for the suggestion. We were there about 2 years ago and had a good experience. However, this time the coach isn't going back to Wisconsin with us - it will be spending the year in New Mexico and we will travel back and forth to it to continue our tour of the area.
Kearn

Re: Aux pump running too much Was: What does this mean?

Reply #20 – March 01, 2016, 08:04:08 pm

"In reply #7 you say the pump was running when you turned the system off but five hours later the coach was still level. If the coach was level why was the plump running?" That's what I'd like to know, too. The smart-alec answer is that computers don't have reasons for doing what they do. Better answer is that something was confused. The compressor sounded normal when it was running, but when it shut off it made a fairly loud noise. It has run in the past, but always was very quiet.

I just checked, and I still have about 65 pounds of air in the tanks. There is a red light on over the AIR button. The compressor is not running, and the coach is still level.

Re: Aux pump running too much Was: What does this mean?

Reply #21 – March 01, 2016, 08:54:04 pm

Is the red light over the air button the excess slope light?
A loud noise on compressor shutdown could indicate the compressor was under a high load (high air pressure) when power was removed.
JD

Re: Aux pump running too much Was: What does this mean?

Reply #22 – March 02, 2016, 08:43:43 am

The red light is over the AIR button.

I wonder if the compressor outlet is clogged. That would explain the loud noise on shutdown and the frequent running. The (confused) sensor was calling for (unneeded) air and the compressor was trying to deliver it.

The air gauges are still showing 65 pounds. Shouldn't they be closer to 0 by now? The engine was shut down a little after 4:00 Monday afternoon and it is now almost 8:00 Wednesday morning.

Re: Aux pump running too much Was: What does this mean?

Reply #23 – March 02, 2016, 09:20:44 am

Quote from: kb0zke – March 02, 2016, 08:43:43 am

The air gauges are still showing 65 pounds. Shouldn't they be closer to 0 by now? The engine was shut down a little after 4:00 Monday afternoon and it is now almost 8:00 Wednesday morning.

The fact that your air tanks are holding pressure is a good thing. It shows your brake tank protection valves are working correctly.

Re: Aux pump running too much Was: What does this mean?

Reply #24 – March 02, 2016, 09:22:48 am

David,
Pressure down to around 65 on a few days then lasting much longer may be normal. That's about the way my coach behaved.
It doesn't sound like you have a serious level problem. You stay level for a reasonable length of time.
If the pump is running and the coach doesn't go up I wonder if the pressure sw is turning the pump on and it's only pressurizing the plumbing up to the HWH manifold because the raise solenoid isn't powered open because the coach is level? Can you remove and check the pressure sw? At least you could confirm something.
You may have more than one problem, that can be confusing, fix one at a time and see what you have then.

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