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Leveling systems, automatic vs. manual

We are trying to understand the leveling system in our coach. We have tried letting the automatic system level the coach, but it can't seem to get it right. So I tried to use the manual leveling procedure. After getting the coach level manually I turn the system off. Within a few hours the automatic system has the coach out of level again. I thought using the manual system would disable the automatic one, but it doesn't seem to work that way. Can someone explain what is happening?
Royce & Denise, MC #17410
'01 U320 4220 ISM450 Build #5895 SOLD
Toad: '10 Honda CR-V

Travel makes one modest. You see what a tiny place you occupy in the world. - Gustave Flaubert

Re: Leveling systems, automatic vs. manual

Reply #1 –
Manual leveling is going to get you level, but isn't going to hold you there if you have an issue.  Automatic leveling will try to re-level you periodically (it checks roughly every 1/2 hour, IIRC).

Can you describe more what is happening - does it seem like one of the air bags is leaking down/one corner sagging?  Manual leveling isn't going to compensate if there's a leak.  If it's a big leak, on auto level the coach will eventually go into "excess slope", meaning it couldn't relevel in the given interval.

Conversely, is one corner rising more than the others?  This could indicate a raise solenoid leaking through (happened to us).  Again, manual leveling isn't going to compensate.  In autolevel you'll get all kinds of weird behavior.

I found taking periodic measurements of the air bag height (measure between the plates), say every half hour or hour helped us understand what was losing air (leak out) and what was "gaining" air (raise solenoid leak through - thanks to Pamela and Mike and Jerry Whiteaker).

If auto level isn't initially getting you level, there's a level sensor that may need to be adjusted.  There are different styles of sensor (and locations) for the different years; someone with a 2001 will have to answer for your year.
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: Leveling systems, automatic vs. manual

Reply #2 –
Not sure about an '01, but on our '03 we have to have the ignition key ON and then press Emergency Stop on the HWH control pad. Otherwise the automatic leveling keeps working.
Dick
Dick, '03 U320 40' Tag, 2 slides, Coach #6075
Full Timers
2009 Honda CR-V

Re: Leveling systems, automatic vs. manual

Reply #3 –
Michelle,

I'm not sure exactly what is happening but you've given me some good hints for figuring it out. I just know that I manually level in the evening and by morning we're out of level to the point that the bathroom door swings open against the hinges with a bang and one side of the shower has over an inch of water that won't drain. It seems low in the rear.

However, I never see an 'Excess Slope' light on so I think the system thinks the coach is level. It seems to indicate a misadjusted sensor.

Thanks for your help and insight. Much appreciated.
Royce & Denise, MC #17410
'01 U320 4220 ISM450 Build #5895 SOLD
Toad: '10 Honda CR-V

Travel makes one modest. You see what a tiny place you occupy in the world. - Gustave Flaubert

Re: Leveling systems, automatic vs. manual

Reply #4 –
One hint that HWH gave me was to wait for 10 minutes or so after landing in the parking spot before hitting the auto level button. The delay gives the mercury (if used) to get back together after being bounced around on the road. The automatic leveling will get pretty close, but can't get it perfect.

Can you tell if the little pump is coming on to maintain level? Also, does the out-of-level condition get worse as time goes on or does it just get to one point and then stay there? In other words, if you are perfectly level at supper tonight, and slightly low in the rear at breakfast tomorrow, what is it like at supper tomorrow night if you don't change anything? If the coach gets to a certain out-of-level position and then stays there that would indicate that that's where the computer thinks is level. If it gets worse then you have some other problems.
 

Re: Leveling systems, automatic vs. manual

Reply #5 –
 :-*
Quote from: BamaFan –

I'm not sure exactly what is happening but you've given me some good hints for figuring it out. I just know that I manually level in the evening and by morning we're out of level to the point that the bathroom door swings open against the hinges with a bang and one side of the shower has over an inch of water that won't drain. It seems low in the rear.

That points to possibly a potential leak somewhere in the rear - because you say "manually level".  Again, if you manually level, the system will do nothing overnight to maintain that setting.  Now, if you sagged at the back overnight while in AUTO level, one would definitely suspect something with the level sensor.

Still, you might think the back is lowering when in fact the front is raising (raise solenoid leak through).  This is why getting actual measurements over time will give you a better picture of what's happening.

Quote
However, I never see an 'Excess Slope' light on so I think the system thinks the coach is level.


"Excess slope" will only happen if you're in auto level and the system cannot level either when it first tries to or later, when it does one of its wake-up cycles..  If you manually level initially all you're doing is setting it at one point in time, but the system is not going to try to maintain that setting. 

ETA -also, in Auto level, the algorithm first checks level status, then lowers (exhausts) air from the high sides if you're not level.  If it cannot achieve level by exhausting, it will then raise (pump up - aux compressor will run) the low point(s) to try an achieve level.  If after all this it still cannot achieve level within a reasonable interval, the system will go into "excess slope" and shut off the aux compressor to protect it.  Again, this only occurs in Auto level.  Manual level won't care what the situation is after you initially level.

ETA2 - now, if you initially try to auto level, but you aren't happy with the results, it could point to a level sensor needing adjustment.  Then if you manually level but the situation changes over time, that would point to a leak as an additional issue.  A common leak point is the o-rings on the HWH manifold "six packs".  Block, chock, get out your Spiderman kiddie bubbles and check the manifolds for leaks.  RAP6554 is the official o-ring kit; here's a post with the o-ring measurements so you can just buy them at a hardware store Our leveling system problem
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