Skip to main content ↑ ↓
Topic: 2005 U270 12 volt air compressor won't shut off. WET TANK location? (Read 635 times) previous topic - next topic

2005 U270 12 volt air compressor won't shut off. WET TANK location?

On my 2005 U270, the 12 volt air compressor  for the HWH slide system will not shut off.
1- for time being to shut it off I have removed the 5 amp blade fuse in line to motor
2- The bladders at slides are tight when checked with credit card
3- I did shut off the valves to the individual bladders, the 12 volt air compressor  kept running
4- The bowls are clean and I can not find any  leaks in the compressor bay

QUESTION- On the air schematic, the compressor feeds a "WET TANK". Where is this "WET TANK" located ?
Any other advice is also greatly appreciated.
Thank you
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #1 –
The air wet tank is located just in front of the rear axle on the passenger side. on our 1997 U320.
40ft 1997 U320

Re: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #2 –
Quote from: cdm –
On my 2005 U270, the 12 volt air compressor  for the HWH slide system will not shut off.

3- I did shut off the valves to the individual bladders, the 12 volt air compressor  kept running
4- The bowls are clean and I can not find any  leaks in the compressor bay

On #3, are those the original valves with black handles or have you replaced them with 1/4-turn brass ball valves?  The original are known to be a leak source.

On #4, can you confirm there is no air leaking out the bottom of the condensate (not the desiccant) bowl - the one with the solenoid on the bottom?  That valve should close when the compressor is running so that no air comes out and is a very common issue.  (it's a normally-open solenoid, it opens when power to the compressor stops so that it can expel the condensate)


Since you have an '05, you likely have a switch marked "air tank" at the driver's left elbow.  Is it off?  Make sure it is (it links the aux compressor to the main coach tanks which should rarely be done).  Put the ignition key in "accessory" or whatever position allows you to read the Driver Information Center without the main engine running.  Do Tank A and Tank B go up in pressure with the aux compressor running and the air tank switch off?  If so, there's a failed check valve and/or solenoid related to the air tank switch.


Last thought - the Square D pressure switch for the aux compressor.  See if it's just not making the upper pressure switch to shut off the compressor.  They do fail.


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: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #3 –
I will check the items listed in the morning and post my findings. Thank you
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #4 –
The wet tank for the 12 volt compressor is in the front. On some coaches there are drain valves for air tanks right in front of the left front wheel. If so the very outside valve is for the 12 volt compressor tank. You should find 3 air tanks in the front. The long one farthest front will be for the 12 volt compressor.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #5 –
ANSWER TO THIS IS YES they are the black handle valves but no sign of external  leak-On #3, are those the original valves with black handles or have you replaced them with 1/4-turn brass ball valves?  The original are known to be a leak source.

ANSWER- I HAVE FOUND AIR LEAKING AT BASE OF GLASS BOWL, ABOVE SOLENOID, ON THE BOTTOM RADIUS PORTION OF THE BOWL WHERE THE FITTINGS ATTACH TO THE GLASS- NEED TO C FIGURE OUT HOW TO TIGHTEN THIS. On #4, can you confirm there is no air leaking out the bottom of the condensate (not the desiccant) bowl - the one with the solenoid on the bottom?  That valve should close when the compressor is running so that no air comes out and is a very common issue.  (it's a normally-open solenoid, it opens when power to the compressor stops so that it can expel the condensate)

There is an AIR TANK switch to drivers left, it is off

Once I fix leak at glass bowl, I will start  coach get read outs at Driver Information Center
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270
 

Re: 2005 U270 12 volt air compressor won't shut off. WET TANK location?

Reply #6 –
Quote from: cdm –

ANSWER- I HAVE FOUND AIR LEAKING AT BASE OF GLASS BOWL, ABOVE SOLENOID, ON THE BOTTOM RADIUS PORTION OF THE BOWL WHERE THE FITTINGS ATTACH TO THE GLASS- NEED TO C FIGURE OUT HOW TO TIGHTEN THIS. On #4, can you confirm there is no air leaking out the bottom of the condensate (not the desiccant) bowl - the one with the solenoid on the bottom?  That valve should close when the compressor is running so that no air comes out and is a very common issue.  (it's a normally-open solenoid, it opens when power to the compressor stops so that it can expel the condensate)

There is an AIR TANK switch to drivers left, it is off

Once I fix leak at glass bowl, I will start  coach get read outs at Driver Information Center

I think you'll find that glass bowl is the problem and you won't need to look further once it's replaced.  The plastics age out over time and thermal cycling and there are likely stress cracks around the fittings at the bottom of the bowl (we have seen one fail catastrophically on an '09 Nimbus).  With air escaping from the bowl itself, the pump cannot build pressure and that's why it continues to run.  You would be best off ordering a new bowl.

Read through Steve's write-up here:

HWH Filters and Bowls
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