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Topic: Troubleshooting HWH air leveling (Read 997 times) previous topic - next topic

Troubleshooting HWH air leveling

I am having trouble with my leveling system and air bags. Here are some of the symptoms.

1. The rear always seem low. Even in travel mode, the front are always higher than the rear. I am not sure the ride height is correct in the rear. I even have tire marks worn in the top of both rear wheel wells. '

Q) Is there a way to adjust the rear travel height?

2. While parked the rear also seems low. If I use the 'Raise' button, the front goes up about twice as high as the rear. The leveling panel will say the rear is low. I don't understand why the rear won't raise up past half way. 

3. We are at a campground now three days. The left rear is now low even though the auto-leveling has been on.

Tennessee RV did fix a few leaks but it does not seem 100% resolved. I am very concerned when the coach lowers onto the tires. It seems that the stops should prevent that but they don't.

Q) If I dumped the air, the entire coach would be resting on the front and rear tires. Is that normal or a problem?

I also have a hunch that the 12v compressor isn't turning on. The coach must be attempting to level by just releasing air or using the remaining air in the travel tank.

Q) How do I test the 12v compressor?
Fred H.
1996 Foretravel U320 4000 Build #4993 (Previous motorhomes 1985 Airstream 345, 1977 Argosy 20)
Sevierville, TN
ViewRVs.com

Re: Troubleshooting HWH air leveling

Reply #1 –
Level on countertop to verify level.  That's what mr Fore designed.

Look at the ride height valves. Rod is adjustable lenght to corect.

Sounds like the fuse is pulled for the 12v compressor
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Troubleshooting HWH air leveling

Reply #2 –
Where would I find the fuse for the 12v compressor?
Where is the compressor?

Sorry if the questions may be simple. I've only had the coach less than 2 months and I haven't had time to really learn it.
Fred H.
1996 Foretravel U320 4000 Build #4993 (Previous motorhomes 1985 Airstream 345, 1977 Argosy 20)
Sevierville, TN
ViewRVs.com

Re: Troubleshooting HWH air leveling

Reply #3 –
My compressor is behind the inverter on drivers side storage bay. 

I don't know where the fuse is, unless inline on 12VDC power wire.
1998 U320 40'
2005 GMC Yukon
MC# 17609

Re: Troubleshooting HWH air leveling

Reply #4 –
I put a simple spade type male/female connection in the 12v positive lead. In that way I can just reach into the bay and easily disconnect the 12v pump whenever I need. No need to get to fuses
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: Troubleshooting HWH air leveling

Reply #5 –
Fred,

The HWH air leveling system is kinda complicated, until you get it figured out.  You've got some studying to do, but after you do some reading, I think most of your questions will be answered.  Try starting here:

Technical Help - HWH
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"

Re: Troubleshooting HWH air leveling

Reply #6 –
On the issue of resting on tires, mine did that so I added and extra 3/4" to the stops and now it clears the tires by just over 3/8 "
I believe the correct ride height can be measured when on level surface by checking the measurement of the the air bags ( outside from top of plate to bottom) it should be 8" or close (I think!!)
See what you have and at least they should be the same all around (again, I think I am right)
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Troubleshooting HWH air leveling

Reply #7 –
Quote from: ViewRVs –
....I also have a hunch that the 12v compressor isn't turning on. The coach must be attempting to level by just releasing air or using the remaining air in the travel tank.

Q) How do I test the 12v compressor?

Newbie comment:

Just yesterday, I was troubleshooting my 12v compressor and found a bad or intermittent circuit breaker (CB).  It's a 40A CB that feeds the high-current side of the aux compressor solenoid (attached to the compressor's mount).  If I understand it correctly the control side of the solenoid is activated by either the pressure switch or the HWH leveling computer. 

Using a DVM or test lamp, check for +12v at the input side of the solenoid.  It will have a fat red wire on the lug.  If no +12v there, check the CB for the HWH compressor on the 12v buss.

If that's all good, between the pressure switch and the solenoid there is an in-line fuse holder with a 5A fuse. Check the fuse with your DVM.  If good take the cover off of the pressure switch.  Ensure that the pressure switch contacts are closed.  If not then close them (you can use your finger since it's low voltage and low current).  As you open and close the pressure switch contacts you should hear the solenoid click pretty loudly each time.  If you don't hear the solenoid click, check for +12v on the control side of the solenoid.  If you have +12v at the control input and have a solid ground connection then you likely have a bad solenoid.  If you do hear the solenoid click and the compressor does not start, check the input lug on the compressor for +12v.  If no +12v at the compressor you likely have a bad solenoid.  If you do have +12v at the compressor and a solid ground on the other compressor lug and it doesn't start, the compressor itself is suspect.

One remote possibility: if you do have +12v at the compressor input but the compressor does not start, then check the operation of the water trap drain solenoid controlled valve.  I discovered yesterday that if the water trap drain solenoid does not open when the compressor turns off, the compressor may not restart due to high residual compressor head pressure.  It's unlikely this will be your issue because if your compressor isn't running at all it shouldn't have any residual head pressure.

Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Troubleshooting HWH air leveling

Reply #8 –
The measurement for ride height is 81/4," from the bottom of the top plate to the top of the bottom plate when coach is level.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Troubleshooting HWH air leveling

Reply #9 –
Quote from: ViewRVs –

Where is the compressor?

On my '96 U295 the compressor is in the house battery compartment behind the panel above the batteries- driver's side opposite the LP tank, adjacent to the driver's side fuel filler.
Elliott & Mary Bray
ex. 1996 36' U295 - Build 4879
ex. 2018 Coachmen Leprechaun 319MB
 

Re: Troubleshooting HWH air leveling

Reply #10 –


Is this the 12v pump? This is on the passenger side.

I can raise the coach with the air pressure from the engine but while parked, the electric pump does not run.  There are some slow leaks which I think is fairly normal. Here are my three issues.

1) The 12v pump does not run
2) The driver's side front value doesn't release air
3) The front ride height is high and the rear is at the minimum ride height

We are considering just taking it to HWH in Iowa and having the whole system checked. It has never been fully operational since we bought it. Tennessee RV did go over it and fix a few things but I am not sure they are as qualified as the folks in Iowa.  Any thoughts?
Fred H.
1996 Foretravel U320 4000 Build #4993 (Previous motorhomes 1985 Airstream 345, 1977 Argosy 20)
Sevierville, TN
ViewRVs.com

Re: Troubleshooting HWH air leveling

Reply #11 –
A visit to HWH is worth the time and miles.  Call for an appointment.  Get there the afternoon before.  They start early.  Fisherman's Corner COE on the Mississippi where I 80 crosses is a nice stop before getting to HWH.

The small compressor is small, maybe 10-12" long, 4 inches in diameter.  There will also be a pressure switch, a water separator bowl, a bunch of wires and air tubing.  Mine is not where yours is so no help there.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Troubleshooting HWH air leveling

Reply #12 –
Quote
I am not sure the ride height is correct in the rear. I even have tire marks worn in the top of both rear wheel wells. Is there a way to adjust the rear travel height?'
Here is an excellent tutorial on adjusting the ride height. (ride height adjustment)) Just make sure you are on a level surface. You can do the measurement with a rule but it's easier if you make a little tool. Here's a photo of mine which is just a couple of nails in a board.

Quote
While parked the rear also seems low.
Foretravel buses look low in the rear to the eye. Just have to do your ride height measurement to be sure.

Quote
Tennessee RV did fix a few leaks but it does not seem 100% resolved.
Those of us that have no air leaks are few and far between.

Quote
If I dumped the air, the entire coach would be resting on the front and rear tires. Is that normal or a problem?
Mine have all done that to varying degrees. For example, my 300 would lay down hard on the rears but my 270 just touches. It's a design defect. You can modify the stops like Roger or just remain cognizant of that "feature" when you are leveling.

Quote
I am very concerned when the coach lowers onto the tires.
This is a leak somewhere. Could be a connection or more likely, an HWH solenoid. If you go to HWH be advised that they will not repair any leaks that are not directly involved in the HWH system. They will, however, mark all they find so you can get them fixed elsewhere. Kinda weird but that's the way it is.

There are many excellent threads here on the forum on your issues. Also, the link I supplied is to beamalarm.com which is also a great resource. And the HWH manual that Chuck provided includes a really great troubleshooting guide.
jor
93 225
95 300
97 270
99 320

Re: Troubleshooting HWH air leveling

Reply #13 –
Air compressor only comes to life when HWH is on and calls for raise when air pressure switch indicates not enough air. Check with volt meter near compressor to see if HWH logic is doing its job, but the compressor is not powered from fuse, switch or connection problem.

BTW, your photo looks like the coach ABS control box, nothing to do with HWS.

Try to self-diagnosis with the very good HWH documentation to see if you can eat away at your problems. HWH will fix HWH problems but will not touch/fix anything that is not HWH related, like ride-height.

Ride height is controlled by three chassis ride height valves. But the HWH 6-pack valves must be working ok for chassis ride-height to do its thing. Ride height valves are easy to adjust, by sliding rubber boot that is held in place with hose clamp.