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Topic: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge (Read 583 times) previous topic - next topic

Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Still hunkered down on a new pad we built due to COVID19. Lately, we're hearing the Aux Compressor come on every 1-2 hours and then at sometime later you'll hear the hiss of air discharge.  The HWH panel blinks Red after the Compressor stops, but then it stop displaying RED after a while.

Does not cycle enough to heat the compressor too much, seems to stop running after 2-3 minutes. Not critical yet, but I just want to fix it while we're here.

I read a few threads but did not see the same conditions that I'm facing. Can anyone give me an idea on what and where to check for air leaks or device failure?

Thanks much, Paul
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #1 –
Do you have the manual for the HWH system?,if so check it out,if not it sounds like your coach may be automatically leveling,if that's the case and the coach is level start the coach and bring it up to travel mode and hit the off button on the HWH,this will shut the
system off(turn off engine),try that and see what happens.PS,father in law was original Screamen Eagle.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #2 –
As an aside, that pump can run for 15 minutes then will shut itself off without any problems. That's it's design.
1994 U280, Build 4490
Deming, NM.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #3 –
My 2000 will run about 5 to 10 min to recharge the air system about every 3 hours, as the air system leaks. The less leakage in your air system the longer it will be before the pump comes on, but of course all air systems leak. 



Charlie and Jennifer Sawyer, et. al.
2000 U320 M-4010 #5625
2015 Rubicon

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #4 –
Paul, there is a pressure release aftr the pump shuts off to purge any water.  If it running for a short while every couple hours it is most likely a small leak somewhere.  These can take lots of time to find and by the time you do another will develop.  Pretty rare that it is a fitting, more common is a check valve or something in a six pack leveling manifold.

If your coach is staying pretty level try pressing the Air button on the HWH panel just once (with ignition on) instead of twice.  This leases it in manual mode.  You can level the coach with the buttons on the pad and the HWH computer will not be signalling the compressor to come on.  I added a switch to my compressor to cut power to the compressor so it will only run if I want it to.  My coach will stay level enough for weeks after a couple adjustments in the first week.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #5 –
So,, my question would be.  IF... you are parked on a level surface is it OK to dump all the air and let the air bags deflate?   

 The part I don't get is if you have a small leak ( like we all do ) and you shut of the HWH level system.  Do all the air bags leak down at the same time or just the line / air bag that has the small leak ???
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #6 –
Would depend on where in the system the leak is,there are some check valves in there.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #7 –
I just noticed something else. Ran up to the panel as soon as the Aux Compressor turned on, The Center Rear level Indicator light turned yellow then as soon as the red lamp fluttering resumed the yellow was off.

Based on that, looks like it's a rear leak somewhere? Are there any typical spots I should be looking at?

Thanks, Paul
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #8 –
Quote from: Bob & Sue –
So,, my question would be.  IF... you are parked on a level surface is it OK to dump all the air and let the air bags deflate?   

 The part I don't get is if you have a small leak ( like we all do ) and you shut of the HWH level system.  Do all the air bags leak down at the same time or just the line / air bag that has the small leak ???
I don't know if all airbags leak down, but the coach is adjusting somewhat.
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #9 –
Quote from: Roger & Susan in Home2 –
Paul, there is a pressure release aftr the pump shuts off to purge any water.  If it running for a short while every couple hours it is most likely a small leak somewhere.  These can take lots of time to find and by the time you do another will develop.  Pretty rare that it is a fitting, more common is a check valve or something in a six pack leveling manifold.

If your coach is staying pretty level try pressing the Air button on the HWH panel just once (with ignition on) instead of twice.  This leases it in manual mode.  You can level the coach with the buttons on the pad and the HWH computer will not be signalling the compressor to come on.  I added a switch to my compressor to cut power to the compressor so it will only run if I want it to.  My coach will stay level enough for weeks after a couple adjustments in the first week.

Thanks, The PO installed a cutoff switch, I'll try your method too!

Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #10 –
Quote from: John44 –
Do you have the manual for the HWH system?,if so check it out,if not it sounds like your coach may be automatically leveling,if that's the case and the coach is level start the coach and bring it up to travel mode and hit the off button on the HWH,this will shut the
system off(turn off engine),try that and see what happens.PS,father in law was original Screamen Eagle.
Airborne!
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Aux Compressor comes on every 2 hours, then sometime later the hiss of discharge

Reply #11 –
Quote from: Bob & Sue –
1.  IF... you are parked on a level surface is it OK to dump all the air and let the air bags deflate?   

2.  Do all the air bags leak down at the same time or just the line / air bag that has the small leak ???
1.  Sure - won't hurt a thing.  My coach often sits like this for weeks between trips.  The weight of the coach is supported by the mechanical stops between the suspension members, so there is no unusual stress on the deflated air bags.

2.  Questions like this can best be answered by getting out your air system diagram and studying the air lines supplying the air bags.  Also, take a look at the HWH Leveling System Service Manual for your system, and learn how the 6-pack manifolds function.

Hint:  There is a check valve in each side of the 6-pack manifolds.  Each manifold has 2 check valves.  Each check valve retains the air pressure in one corner of the coach.  IF all 4 check valves failed simultaneously, then all 8 air bags might deflate at the same time.

(There are other ways all 8 bags could deflate at the same time, but they would also require extraordinary simultaneous failure of multiple individual system components, which is IMO highly unlikely.)
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"