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Topic: My auxiliary HWH air compressor will not shut off-HELP (Read 1995 times) previous topic - next topic

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #25 –
Good work John, now you'll have a better idea of what is going on.  Out of curiosity, what is the pressure when your compressor starts running and stops running now?  Mine was 65psi - on and 85psi off.  This small range meant it didn't run as long, but more frequently.  I have changed out the pressure switch so mine now comes on at 65psi and off at 120psi.  It does run longer, but less frequently.
Keith
2003 U320 38' #6197

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #26 –
Keith,

I had not specially checked to see when the pressure switch would turn the auxiliary air compressor "ON" and "OFF".  So today I opened the drain valve to the Air Seal Slide Out Bladders/ACC. Tank.  My pressure switch turned the auxiliary air compressor "ON" @ 60 psi and "OFF" @ 84 psi .  My auxiliary air compressor took 1 minute & 22 seconds to bring the pressure back up to the shut "OFF" pressure.  These "ON"/"OFF" pressures are only as accurate as my pressure gauge (±1.5% of span [Liquid filled]).  Currently, it appears the auxiliary air compressor is coming on about once very 24 hours (excluding the times it might come on to re-level the coach when parked). 

John

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #27 –
At the frequency of once per day, I would leave it alone.  Mine would run every few hours, so changing the control switch to a programmable one allowed me to set a larger differential of pressure. 
Keith
2003 U320 38' #6197

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #28 –
Follow up question to this thread.  I have a 2002 U320.  I am getting ready to start chasing down a potential air leak in the leveling/slide air system.  I have a pressure gauge on my aux air pump discharge.  It runs when the leveling system calls for it, but I also have a toggle switch on the pump (it runs when leveling calls for it even if it is in the off position).  I used to leave this in the on position all the time since that is how it was when I purchased 2 years ago. 

Recently, I noticed the aux pump running continuously which it never had done before.  I checked the pressure on the gauge and it was 85psi.  I turned the toggle switch off and the pump stopped.  After it cooled off, I turned it back on.  The gauge shows a discharge pressure of about 10-20 psi initially and over about 2-3 minutes builds to about 85psi but never turns off.  I suspect that I have a small leak somewhere in the system that is not letting it get fully up to the pressure switch setpoint.  No obvious air leaking sounds. 

Where are the air fittings for the slide system physically located. I recently had some work done on the slide air system by MOT and suspect that may be where the leak is.  (I will use soap and water for all of the fittings I can find in the compartment where the pump is, just curious where else I should check). thanks. (note, I already purchased a compressor rebuild kit and will rebuild the compressor following Steve Cooks great post, but I want to find and fix any problems before I rebuild it)
John "Kelly" McDowell and Naida McDowell

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #29 –
Kelly,

First thing to check is the bowl with the NO (normally open) solenoid on the bottom.  If the solenoid isn't sealing when it closes when the pump is running or if the bowl has cracks in it, you won't build pressure.  Feel around the bottom of it - usually it's so much air you won't be able get sustain bubbles enough to do a normal leak check.

HWH Filters and Bowls

That NO solenoid is notorious for leaking - stuff can foul the plunger seat.  I believe it can be rebuilt with one of encantotom's HWH plungers - hopefully others can chime in and confirm, since I'm not 100% positive on the seat diameter  Replica HWH Plungers Redux

Dan will likely chime in to check the Square D pressure switch for the compressor as well if I don't beat him to finding his posts on it.

Aux air compressor

Aux 12 volt compressor compartment "thumping" sound (actually air unloader)

And another discussion of the pressure switch confirming part numbers Auxiliary Air Compressor only able to pump up to 60 PSI
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #30 –
I would go all around the slide .bladder listening for the hissing sound, possible tear in your bladder. I had one bladder tear that I was able to seal from the outside. I also had a bladder tear that I could hear but I could not see it.

While I was typing this I was thinking I don't think I ever talked to someone that didn't have a leaking bladder when they said the compressor keep running.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #31 –
Quote from: turbojack –
While I was typing this I was thinking I don't think I ever talked to someone that didn't have a leaking bladder when they said the compressor keep running.

We did, at least 3 times where it was the unload solenoid valve on the clear bowl I mentioned.

Steve will tell you it was his "A Christmas Story" furnace nemesis.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #32 –
thanks for the troubleshooting tips.  I will take a look at these this weekend and let everyone know what I find.
John "Kelly" McDowell and Naida McDowell

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #33 –
On my rig, when the leveling system wants to raise the air compressor runs even if the pressure switch is satisfied. I have had it try so hard to lift one corner that the compressor ran and opened ed the relief valve. Now if it doesn't level easy in one or two shots, I move.
Dennis Haynes
Bohemia NY
2008 Nimbus 342 SE Carlyle
Build #6475
Motorcade #19148

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #34 –
And some other things to look for, just to keep you busy ;)

sb10.jpg If it is a slide bladder leak, and I hope its not, then you can turn off the air to whichever bladder is leaking, there are shutoff valves on each manifold.  One thing that might happen (at least it did for us), the first time I shut off the air supply to the bladder using that shutoff resulted in that valve leaking.  Ended up having to purchasing a couple of compact 1/4" valves from the hardware store to replace the OEM ones.

The selected media item is not currently available. Another potential air leak location is the slide bladder regulator which is located on the bladder manifold.  @Dick S has a great write up on this issue and the repair.
2000 / 36' / U320 / WTFE
WildEBeest / "Striving to put right what once went wrong"

Re: My auxiliary HWH air compressor will not shut off-HELP

Reply #35 –
As Steve said you can turn the bladders off. First thing I would do before chasing down the leak is turn the bladders off.  If that stopped the air leak, then turn one on until you see the leak again.  Then you will know what bladder to look for.  If it did not make a difference then you know not a bladder leak.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago