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Excessive Compressor runs?

New owner of 2014 IH45. Previous coaches were Tiffin Bus and Newmar Dutch Star, so new to the HWH air systems. Been camped now for almost a week/parked. We are FT. I noticed the compressor down below will come on 2-3 an hour for 1-2 min and less so at night. I was told thats just "coach leveling/use of other air system tied things like doors/etc".

On suggestion from service person, I have started the coach a couple of times over 7 days and aired up the tanks but I still heard the aux compressor kick on shortly after shutting down the coach but this time only about 20-30 seconds and then off.

It makes sense that the HWH is likely trying to keep everything level. Just wondering if the frequency of the compressor coming on and only running a couple of min at most is normal?  Pre-sales service did "fix" a couple of air leaks. I noticed the compressor was coming on about every 10 min before purchase during extended viewing of the coach. 

Re: Excessive Compressor runs?

Reply #1 –
Quote from: tsonby –
New owner of 2014 IH45. Previous coaches were Tiffin Bus and Newmar Dutch Star, so new to the HWH air systems. Been camped now for almost a week/parked. We are FT. I noticed the compressor down below will come on 2-3 an hour for 1-2 min and less so at night. I was told thats just "coach leveling/use of other air system tied things like doors/etc".

It makes sense that the HWH is likely trying to keep everything level. Just wondering if the frequency of the compressor coming on and only running a couple of min at most is normal? 

Even with the more complex system of an IH45, the frequency is not normal.  There's an air loss somewhere.

Boring, I know, but sit and watch the HWH control panel for the "wake up" cycle to see if any amber corner lights come on when it wakes up to show leveling is needed.  That can help give you a direction to look.

You mentioned doors.  Are there air-activated doors in the coach?  If so, are there any manual valves you can turn to isolate the air plumbing to the doors?  I know for the pre-IH45 coaches there are ones for the slide bladders.  If you close those valves and the compressor frequency decreases, it would point to something related to the doors.  You can repeat for the slide bladders (just as an FYI, the bladders seem to have a 7-10 year lifespan, at least in the earlier coaches).  They're rubber, kind of like a heavy duty bicycle tire tube, so they do age out.

Re: Excessive Compressor runs?

Reply #2 –
The 2014 IH45 has Active Air.  This adds a few more air valves to the system with computer control.  As far as the basic air system it is almost exactly the same as older coaches with out AA but have slides. When I got my coach I would almost never hear the compressor run, except for when I was running a slide in or out without the engine running.

This last year started the hunt for the air leak(s) and feel like I am playing wack a mole.  When my compressor would run it would run for what seemed like a few minutes, but I have never timed it, so it could be less then a minute.

I think if you hear the compressor running a few times in the night you have some more air leaks. When the compressor runs more then one per night I will get up, go out and pull the fuse that is just in front of the compress. This shuts the compressor off except for when you  try to raise part of the coach.

I never use Auto Level so it does not try to re level until I do another manual level.

Re: Excessive Compressor runs?

Reply #3 –
Quote from: Michelle –

You mentioned doors.  Are there air-activated doors in the coach?  If so, are there any manual valves you can turn to isolate the air plumbing to the doors?  I know for the pre-IH45 coaches there are ones for the slide bladders.  If you close those valves and the compressor frequency decreases, it would point to something related to the doors.  You can repeat for the slide bladders (just as an FYI, the bladders seem to have a 7-10 year lifespan, at least in the earlier coaches).  They're rubber, kind of like a heavy duty bicycle tire tube, so they do age out.

The 2014 IH has air doors for the bedroom and bathroom.  The valves for these two doors along with the valves for the bladders is located in the same compartment as the air compressor, inverter/chargers, and the hydraulic pump for the slides. They are located on the right side wall. The slide bladder controls have valves where you can turn off the air. Try turning those off and see if that stops the compressor from running or slows it down.

If you want you can PM me with your phone # and I will call you to discuss.

Re: Excessive Compressor runs?

Reply #4 –
Thanks for all the replies.  I will spend some time in the manuals today... interesting they have a LOT more diagrams then I ever saw with Tiffin or Newmar. 

I was wondering if the compressor really need to be running if we are stopped/camped for long periods.  I was thinking of pulling the breaker but wasnt sure the doors would still work.  Perhaps just put the breaker back in once or twice a day would at least reduce greatly the runs. 

When it was in for pre-sales service, I watched the guy fix two leaks and when he was using the HWH panel on the dash to diagnose.  I noticed the levels seemed to hold there once he was done but I will check that out again. 

They did replace one bladder before we took delivery too. 

Noticed when I did start up the engine and let the air build up over 120 in each tank, after about 30-40 min I checked the display on dash and they were already down quite a bit.  Tiffin was like that but had jack-leveling system so it wasnt that big a deal.

Heavy rain here all day so spending time in the bay/outside is probably not likely  :D ...good time to deep dive manuals. 

Re: Excessive Compressor runs?

Reply #5 –
Here are pictures.  You can look at the display and it will tell you what the pressure is in HWH system.  If the SYS goes down fast you have a good air leak.  I don't remember what the cut in or cut out pressures are.

Also picture of compressor with the fuse that I pull that is in front of compressor.

Picture of bladder controls with shut off valves at the bottom on the wall.  The air door controls are above these.

Re: Excessive Compressor runs?

Reply #6 –
Your system is newer than mine, but if it works similarly, then I believe the reason the pump is running is because the system is calling to air up one corner/side/end of the coach.  In my 03, if the HWH system calls to raise any corner, the pump will run regardless of the amount of pressure in the tank(s).

To combat this, I added a delay relay to the wire from the HWH system that called for the compressor to come on.  This is adjustable from .6 to 60 seconds.  I have mine set at about 25 seconds.  If the system tries to raise and can do it within 25 seconds with the pressure in the tanks, then the compressor never runs.  If not, it will turn it on at that point.  Here's the relay:  McMaster-Carr  Simple one wire in and out.

It's in this thread when I replaced the entire stock compressor:  Aux air pump system replacement

I also added a pressure gauge for the HWH tank and a disable switch inside the coach above the microwave, so I can shut it off for the night before going to bed.  Seen here:  Added AUX system gauge and disable switch

Re: Excessive Compressor runs?

Reply #7 –
Quote from: turbojack –
Here are pictures.  You can look at the display and it will tell you what the pressure is in HWH system.  If the SYS goes down fast you have a good air leak.  I don't remember what the cut in or cut out pressures are.

Also picture of compressor with the fuse that I pull that is in front of compressor.

Picture of bladder controls with shut off valves at the bottom on the wall.  The air door controls are above these.


 I did a system check with engine on, auto leveled again and then checked my pressures (see pic).  They have held (fronts and Sys) to those levels for well over 10 min.  Same time seems like on queue about 10 min after engine shutdown with full air (135 psi) in front / rear the aux compressor came on for 2 min again. 

So my suspicions would be a bladder leak then somewhere, since level has nothing on rears and front bags appear to be holding fine.

I would expect next steps would be to get into the basement / airline connections and see if (can I do this?) capping off each room changes the behavior of the Aux compressor.  Make sense?

 

Re: Excessive Compressor runs?

Reply #8 –
Quote from: turbojack –
Picture of bladder controls with shut off valves at the bottom on the wall.  The air door controls are above these.

Is this a quarter-turn shut off for the slide bladder?  (excuse the crude markup)

If so

Quote from: tsonby –
I would expect next steps would be to get into the basement / airline connections and see if (can I do this?) capping off each room changes the behavior of the Aux compressor. 

there would be no need to cap off, just close the valves.  If the behavior improves, open one at a time to see if/when the compressor starts running frequently again.

Note that you do need those valves open to pull vacuum/deflate the slide bladders in order to extend/retract the slides.

(ETA - if those are the plastic quarter turn valves that were also used in older coaches, they are notorious for leaking.  Many of use replaced them with quarter-turn ball valves.  Try soaping them as well, just in case it's one or more of them leaking)

Re: Excessive Compressor runs?

Reply #9 –
Yes 1/4 turn

I have also had to replace all 4

Something else is going on here  for that compressor to be running 10 minutes after shutting engine off with full air pressure 

With key on select manual air (not exactly sure what it says)  Press the buttons to make sure coach is level  Then turn key off. Now wait and see what happens. I never use auto level so this problem may have something to do with auto level

Oldscout will be chiming in if he knows something different

Re: Excessive Compressor runs?

Reply #10 –
The HWH display/dash still shows LF/RF front holding 96 psi.  System was at 131 has dropped slightly in last 4 hours to around 120 (from org 131).  all rears bags on show 0 as they did when it leveled. 

I tried the manual but it shows level too.

I closed all four values on the room slides, unfortunately the compressor still came on about 20-25 min later and again about same period.  I then shot soapy water around all connections for room and compressor but nothing bubbled that I could see so not likely. I have opened up the values again for the bladders and pulled the 5 amp fuse for the compressor for the moment.  I am going to see if the doors will continue to operate.  Thinking they are the last part I did not eliminate.

Should be ok w/o the AUX air compressor running for at least the time being I would think.

Thanks all again for pointing me to the logical places to start.  Hopefully at least narrowing it down more.

Re: Excessive Compressor runs?

Reply #11 –
Quote from: tsonby –
The HWH display/dash still shows LF/RF front holding 96 psi.  System was at 131 has dropped slightly in last 4 hours to around 120 (from org 131).  all rears bags on show 0 as they did when it leveled. 

Is the rear of the coach completely squatted in order to be level?  I'm surprised you're showing 0 psi in all drive/tag airbags.

Re: Excessive Compressor runs?

Reply #12 –
Quote from: Michelle –
Is the rear of the coach completely squatted in order to be level?  I'm surprised you're showing 0 psi in all drive/tag airbags.

Yes showing 0. The spot really appears to be very level to begin with.  concrete.  There is a bit of space from front tires and body (my Tiffin used to sit right on the tires in front when it squatted) and the rears appear to be all the way down visually.

Now that I have the fuse pulled, I am going to sample the HWH display for a couple of hours to see what the SYS levels stay at.
 

Update... just rechecked. both fronts are still at 96 but after about 6 hours the SYS air is down to 65 now.  perhaps one of the bags is the culprit after all

Re: Excessive Compressor runs?

Reply #13 –
So if you're overall low when level, can you manually (or force) level at a higher "height" (so there's air in all 10 bags and you're level to start), then watch the bag pressures?  See if one or more is leaking down fast before the aux compressor fires up. 

Re: Excessive Compressor runs?

Reply #14 –
I don't think the air bags are the problem if front bags staying at same pressure.  Looks like you have a leak somewhere. You have an air tank in front passenger side compartment and one  in front of tire drivers side that are use for HWH. Good chance leak around there.

I believe compressor comes on at 85 psi so it should not be coming on unless hwh tells it to



Re: Excessive Compressor runs?

Reply #15 –
Quote from: turbojack –
I don't think the air bags are the problem if front bags staying at same pressure.  Looks like you have a leak somewhere. You have an air tank in front passenger side compartment and one  in front of tire drivers side that are use for HWH. Good chance leak around there.

I believe compressor comes on at 85 psi so it should not be coming on unless hwh tells it to




Quote from: turbojack –
I don't think the air bags are the problem if front bags staying at same pressure.  Looks like you have a leak somewhere. You have an air tank in front passenger side compartment and one  in front of tire drivers side that are use for HWH. Good chance leak around there.

I believe compressor comes on at 85 psi so it should not be coming on unless hwh tells it to




Think you are likely correct.  I went ahead air up the coach to 130 and put some air in the other bags on the coach.  After about 2 hours the only drop was in the SYS number (See pic).  Since I believe I have eliminated bladders and no connections in the bay it self showed any leaks when I did soap tests, then next steps would be to start tracing and testing I guess.

I still have the fuse pulled and will prob leave it out for now.  if I run the coach once or twice a day for 5 min that should air up systems as needed.

Thanks again all for advice and help.    Not a crisis issue but a good learning day all the same.

Re: Excessive Compressor runs?

Reply #16 –
So since you have the fuse out the compressor has not run at all?

Re: Excessive Compressor runs?

Reply #17 –
If you have air in the bags and they are not dropping then everything is good in that part of the system. Since you are seeing a leak down on the  HWH "SYS" of around 7 psi per hour, then you have a fairly good leak in the system somewhere. There are two air tanks that handle the HWH systems and other air needs.  The valves for the bed and bath air doors, along with the bladder controls are on the wall where the compressor is located. In front passenger side compartment there is an air tank and on the front wall is the air control for the step cover. Those two cabinets are the easy to get to locations to find leaks. From there  you have to go under the coach. If you get under it, make sure you have jacks stands for the front and tubes that go between the frame for the back.  If system dumps air it only takes a second or two to dump the air from the bags and drop. In the front of the coach their are 3 air tanks.  The one in center in front of axle is for the front brakes, and center behind front axle is rear brakes. There is an air tank on drivers side in front of the tire that is the other HWH tank.  I have had leaks at all 3 locations, plus at the tank in front of and behind the front axle.

You do NOT need to be running your coach engine a few times a day to keep the pressure up, If you are wanting to keep the pressure up, then go and plug in the fuse and let that compressor run.  When parked the the only air use you have is if on Auto Level, the coach trying to relevel, when opening or closing the bath and bedroom doors, and to keep a pressure on the bladders so they stay sealed against the  slide out.

I had tried using dawn soap and water, but learned that does not do a very good job of looking for air leaks.  Others said to use kids bubbles and I now keep a jar with a sprayer in the coach.

 I do not like auto level so I use manual level and coach stays level until I leave. 

Re: Excessive Compressor runs?

Reply #18 –
Thanks Turbojack. 

Yeah all bags seem to be holding fine.  I dont think there are any bladder leaks since I closed all those values for a good 2 hours and still see the leak down/Aux run. 

At this point I am pretty much doing what you suggested...leaving the fuse out until we go to bed, airing up the tanks with it, then pulling it, just so we have doors in the morning.  I dont plan on starting the coach any more as part of air recovery.  That was mainly for troubleshooting and research.

I havent started the hunt underneath yet (waiting for a bit better weather here too) and everything seems stable at the moment.  I need to get some better detection liquid too.  Will try out the kids bubble stuff.

I was toying with taking it back to MOT for a day but they were pretty ambivalent about chasing non-obvious leaks. 

Over the years of owning big RVs.... I have learned things annoy me a LOT more then the dealers and service folks.  Of course they would prob feel different if they were going home to the unit at night too.

Good tip on the jack stands.  I was somewhat spoiled getting under the my Tiffin Bus since it was hydraulic jacks.  I noticed for the first time too that I need the front wheels straight when going into level (auto or otherwise) Clearance as really close on the body work if those were turned out at all.  Prob same from my bus and I never noticed...just lucky I guess.

Re: Excessive Compressor runs?

Reply #19 –
I have bought the Amprobe ULD405  So far it is has found a few air leaks.  Before I replace fitting I double check with bubbles.  Not sure what part of the world you live in but I am going to be at the New Ibera Motorcade event  First week of May so if you go I will be more and willing to let you check your coach.