Skip to main content ↑ ↓
Topic: How often should air compressor kick in? (Read 684 times) previous topic - next topic

How often should air compressor kick in?

New owners of a 2003 U320 are wondering how often the air compressor normally kicks in.  Does 3-4 times daily indicate a problem or is this normal?  We've discovered that if a bay door is left open in cool weather, it runs even more often.

Re: How often should air compressor kick in?

Reply #1 –
I think you will find that is about normal. I have found I have small leaks and it will kick in more as I sit longer.  It tries to keep my tanks at 30lbs so I know that it takes a couple days to get there now and that is fast then it used to be.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: How often should air compressor kick in?

Reply #2 –
Quote from: jlnewby –
New owners of a 2003 U320 are wondering how often the air compressor normally kicks in.  Does 3-4 times daily indicate a problem or is this normal? 

How long does it run for?  Just a brief pump up or a long run?

Is the coach being actively releveled when this happens?  You can tell by looking at the HWH control panel to see if there are any amber lights.

3-4 times daily isn't out of the question, especially if there are temperature swings during the day.  There could be tiny leaks but nothing serious, especially if it's not a long pump time.
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: How often should air compressor kick in?

Reply #3 –
Quote
"It tries to keep my tanks at 30lbs so I know that it takes a couple days to get there now and that is fast then it used to be."

I was not aware the aux air compressor pumped air to the 2 tanks.

What am I missing?
1999 U320 40' 1200 watts on roof. 12cf AC/DC Cold plate fridge/freezer. VMS 240 CL Honda Element

Re: How often should air compressor kick in?

Reply #4 –
Start checking for leaks, especially any lines in that bay( cold contracts, might make leak slightly worse. 3-4 x a day too much. My leaks were at lines right by 12v pump due to vibration of pump I think
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)

Re: How often should air compressor kick in?

Reply #5 –
Quote from: Paul Smith –
I was not aware the aux air compressor pumped air to the 2 tanks.

It doesn't, unless you have a switch labeled "air tank" next to the driver and switch it on.

Maybe John's aux compressor system has been modified from standard.
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: How often should air compressor kick in?

Reply #6 –
Thanks! No air tank switch here.

best, paul

Quote
> On: Sun Dec 28, 2014 Paul Smith Wrote:
Quote

I was not aware the aux air compressor pumped air to the 2 tanks.

It doesn't, unless you have a switch labeled "air tank" next to the driver and switch it on.

Maybe John's aux compressor system has been modified from standard.
1999 U320 40' 1200 watts on roof. 12cf AC/DC Cold plate fridge/freezer. VMS 240 CL Honda Element

Re: How often should air compressor kick in?

Reply #7 –
Thanks for all of your responses!  At least we are reassured that we probably don't have a major problem, if any.  We are in the desert southwest so there are pretty dramatic temperature swings right now.  We also have an air tank switch which is off.  When parked, does the air compressor keep the slide bladders full & the leveling system operating - directly rather than through the two air tanks?

Re: How often should air compressor kick in?

Reply #8 –
Mine is suppose to keep the tanks with some air.  I questioned that and I think that a couple units after me they put a switch in place.  I checked my air system and then had Keith R at. MOT go over it. We did lower it to 30 lbs from 65.  I also have a garage and the system is aired up past the 30 pounds outside of the tanks. 
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon
 

Re: How often should air compressor kick in?

Reply #9 –
Quote from: jlnewby –
We also have an air tank switch which is off. 

Yup - that switch is best left off unless you're at a campground and want to start airing up before leaving without starting the coach itself.  Now, if the solenoid valve operated by this switch were to be leaking through (and adding air to the main tanks), it could cause the pump to run more frequently and you can test for this by watching the A and B tank pressures on the Driver Info Center when the aux compressor is running (and the air tank switch is off).  You'll need to put the ignition to accessory to power up the Info Center display, but don't start the coach.

Quote
When parked, does the air compressor keep the slide bladders full & the leveling system operating - directly rather than through the two air tanks?

Exactly what it's for.  Now, you may find a few very minor leaks in the aux compressor bay might be causing it to run more frequently (but again, 2-3 short runs in 24 hours isn't abnormal).  The 1/4 turn valves for the slide bladders are themselves a frequent source of small leaks.  Many of us have replaced them with ball valves from the air compressor section of Home Depot or Lowes.  Some of the other connections around the compressor, especially the push-connects can be sources of small leaks.  Lastly, the condensate bowl and desiccant bowl for the aux compressor do eventually need to be replaced since the plastic will age and cracks will appear. 

These last items are something to do on a boring day when you feel like playing with kiddie soap bubble solution. 
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