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Topic: air bags on left side flat can't drive (Read 1234 times) previous topic - next topic

air bags on left side flat can't drive

 I have a 1998 U 290 motorhome and my wife and I started to leave in our motorhome this morning and the front and rear air bags on the left side did not have much, if any,  air in them.  The right side bags are inflated making the coach so low on the left I am afraid to drive it.  When we bought the coach the leveling system did not work and MHT worked on it and said it was fixed, but when we got home it still would not work and because it was a used coach with no warranty we just did not use the leveling system and everything has been just fine as most places we stay are level anyway.  Big problem is now the left side air bags are flat and the right side are inflated and I can't drive it to MHT until i get air in the left bags.  Help any ideas???

Thanks folks we are kind of stuck,

John

Re: air bags on left side flat can't drive

Reply #2 –
The emergency leveling procedure linked by Doug (above) assumes a faulty leveling (height control) valve.  There are 3 of these valves on your coach - one in front and two in the rear.  The two rear valves control the height at both corners in the rear.  The single front valve controls the height at both front corners.  Failure of a rear leveling valve will normally only affect one corner in the rear.  Since you are having trouble with both the front and rear corners on one side, I am thinking your problem lies elsewhere.

Since both front and rear bags (on one side) are affected, I doubt you have a mechanical problem with the 6-packs.  The only time the front and rear bags operate together on one side of the coach is when the HWH control panel calls for a "lower" or a "raise" on that side.  Since you are not able to "raise" one side of the coach, I think it more likely there is a electrical problem causing lack of communication between the control panel and the front and rear 6-pack manifolds.

I will make the same suggestion to you as I just did in another concurrent "leveling problem" thread.  You might try running the trouble shooting steps in the HWH Service Manual.  Doing so should help you determine exactly what component is acting up.  It is important to follow the steps precisely as listed - do not skip steps or assume something is working properly.

https://www.hwhcorp.com/ml11148.pdf

You can also look at the tech links on beamalarm.com (below) to see if any of the trouble shooting procedures match your symptoms:

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
"It goes without saying..."

Re: air bags on left side flat can't drive

Reply #3 –
Thanks for the advise i will be trying it in the morning.  One thing i found out tonight messing with it is that when this first started this morning i saw that the left side was lower than the right but when i started the coach, which had been sitting about 3 weeks, the left side came up.  We drove a few miles and i noticed the bottom air pressure gauge losing pressure dropping to about 90 psi and then it would pump back to 110 psi and start slowly losing again.  We turned around and drove back and now the left side is down and will not come up but the air loss is gone.  Both gauges are holding 110 psi.  So bottom line is i no longer have an air pressure loss but the left side will now not come up at all.  I did soap the air bags and did not find a leak but there is not much pressure in them.

John

Re: air bags on left side flat can't drive

Reply #4 –
Quote from: JBC300 –
  We drove a few miles and i noticed the bottom air pressure gauge losing pressure dropping to about 90 psi and then it would pump back to 110 psi and start slowly losing again. 

John,
Your compressor is making air and the governor is working by what you describe.

Quote from: JBC300 –
Both gauges are holding 110 psi.  So bottom line is i no longer have an air pressure loss but the left side will now not come up at all.

You had to be out of travel mode to do the soaping of the air bags and snooping around. With this latest info that sounds like the left rear ride height valve has either failed or the linkage has come loose. Being out of travel mode takes the ride height valves out of the air loop. Take a quick look at this as you start the troubleshooting that Chuck has linked to above. If this valve has failed it can torque the coach over to look like the front is sagging.

With you saying "not come up at all" is that going into travel mode or is that with you trying to manual level with the HWH control pad or both?

Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: air bags on left side flat can't drive

Reply #5 –
The travel mode light is on even with the coach sitting on the tires.  If i try to level the coach in the auto level mode it does nothing.  The travel mode light goes out and the "air light" comes on but nothing happens.  If i go into the manual mode and push the raise button the raise button blinks but nothing happens.  If i push other buttons it looks like it is working but nothing happens and if you push them long enough the travel light comes back on.  The leveling system has never worked right since i have had the coach so i have never used it,  The first day i had the coach i used the leveling system and did not think i was going to get it to dump and get the travel light back on so we just have never used it again.

THANKS EVERYONE FOR THE HELP SOME HOW I HAVE TO GET IT TO MHT.

John

Re: air bags on left side flat can't drive

Reply #6 –
John,
There are two parts to this HWH system.
The travel system that only uses the top solenoids on each manifold. When the green travel lite is on you have power going to all four travel solenoids holding them open so the ride height control valves can set the travel height. But the lite only tells you power is sent from the computer to the travel solenoids.  It doesn't know if it is getting there or if any of them open.
That system isn't working.
When you go into the level system only the center dump solenoids and the bottom raise solenoids can operate either by computer commands or manual commands from the control pad.
That system isn't working either because you can't manually raise the coach.
Only one system at a time can work, never both.
Think I would check the cable connection on the back of the control pad and the other end of that cable at the computer.
If that doesn't change anything with the history of this system not working I think I would send the computer to HWH for a checkup.
Many possibilities here and troubleshooting when you have more than one thing wrong is certainly more difficult.
John Duld
1995 U320C SE 40'

Re: air bags on left side flat can't drive

Reply #7 –
Quote from: JBC300 –

THANKS EVERYONE FOR THE HELP SOME HOW I HAVE TO GET IT TO MHT.



Your profile says you're just north of Longview, TX, correct?  Just so we know how far (and what kinds of roads) you're dealing with.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

Lifetime Escapees' member SKP 82766
Former 1999 30IB Lazy Daze (2000-2004)
Former 2003 U320 (2004-2016)
Former 2017 LTV Unity (2017-2023)
Shopping for our next coach

Re: air bags on left side flat can't drive

Reply #8 –
I am located on Highway 271, Pittsburg, Tx  which is about an hour north of Tyler.

Thanks again I now think i also have an air leak.  When and if we figure it out i will post the cause of the problem.

Thanks,
John

Re: air bags on left side flat can't drive

Reply #9 –
John,

If you are not able to regain control of the 6-pack valves by using the touch panel, and still want to get the coach moved to MOT (or where ever) then I can only think of two solutions.

1.  Hire a towing company that can put the whole coach up on a roll-back truck or low-boy trailer and move it.

OR

2.  You might be able to manually pressurize the air bags on the "low" side of the coach.  This would require removing the air lines (that go to the air bags on the low side) from both of the 6-pack manifolds.  There are 2 lines on the front manifold that you would remove, and 2 lines on the rear manifold.

Using the proper fittings, you could tie the 2 front air bag lines together with a "T" connector.  Put a short nipple and a valve in the 3rd hole of the "T" connector.  Stick a male quick connect air line fitting in the valve.  Then use your tire filler hose to air up the front bags to the correct ride height, and close the valve.

Then do the same thing in the rear.  Assuming the air bags are not leaking, they will hold air pressure (and the correct ride height) indefinitely.  This will get the coach level at ride height, and allow you to drive it to a repair shop.

If it was me, I'd avoid towing if at all possible.  But it's your choice, so do what seems best to you.

Let us know what happens, so we know the end to the story.
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
"It goes without saying..."

Re: air bags on left side flat can't drive

Reply #10 –
Peck on the down side ride height valve pretty good.. take lever loose and work it up and down.. May have already been mentioned but worth a try and I've seen it work before on air ride.
Dub McBride 1996 270

Re: air bags on left side flat can't drive

Reply #11 –
Quote from: JBC300 –
Thanks again I now think i also have an air leak.  When and if we figure it out i will post the cause of the problem.
The air leak could be the cause of the airbag problem.

P
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: air bags on left side flat can't drive

Reply #12 –
Have a YOUNG man that has a foretravel and he is going to come look at it this week.  I have seen him fix things that stump a lot of people on Motorhomes.  When we get it fixed i will post the results here and again thanks for all the help.

John

Re: air bags on left side flat can't drive

Reply #13 –
Latest info we did find a busted airbag on the rear left and we are going to try to replace it.  We also did get the air leveling system somewhat working but are going to have to get the air bag fixed before we can do much else.  Clamped off the air line to the bad air bag and was able to raise the left side about 80% of where it should be using the one good left rear air bag.  If i get this one changed i promise i have learned a lesson and am going to change the other 7 bags.

Once again thanks everyone for the help

John

Re: air bags on left side flat can't drive

Reply #14 –
Tubeless tire repair plug will usually cure the problem until you can get a replacement. The hole usually faces the tire and was the rear bag on the left rear on ours.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: air bags on left side flat can't drive

Reply #15 –
Mine was the rear bag on the left and had an area about 1 inch tall and 2 inches long that was just rotted and really no place to patch.  We got the old one off and the new one is supposed to be here tomorrow and hope that fixes the problem.

John

Re: air bags on left side flat can't drive

Reply #16 –
If you have had problems with the leveling system all along, it is well worth your time to send the control box back to HWH. Surprisingly their turn-around time is pretty good (3-5 business days). I took pictures of where the cables connected, then removed the box and sent it - along with the touch pad - back to HWH.
They replaced a relay and a switch - and did a good diagnostic check on those components, so that when I reinstalled them i had eliminated a couple of large variables from the problem-solving equation. Ultimately, we found that a loose connection to the motherboard inside the control box was the final thing that needed to be secured - and - we could then lift the unit off the front tires and be on our way!
This problem - and the sleuthing you do to figure out the problem - will add to your skill set and increase confidence in being able to tackle most of the things that pop up on our vintage units.
Good luck with the search
Woody & Sandy Lloyd
1993 Grand Villa
Unihome U280
Cummins / Allison
Build # 4379

Re: air bags on left side flat can't drive

Reply #17 –
I now have the coach back level again.  The problem was the left rear air bag and we replaced it yesterday and the coach is now level and in the travel mode.    As far as the leveling system not working i seem to have maybe fixed it also.  Everything is pumping up and now we can dump the rears bags however I think i also have a stopped up dump line on the front.  If you have about 20 min to hold down the dump switch it finally goes back into the travel mode.  I am thinking about changing the other seven air bags myself as we learned a bunch by doing the left rear one.

Once again thank you all for the help could not have done it with out the support.

John

Re: air bags on left side flat can't drive

Reply #18 –
Quote from: JBC300 –
however I think i also have a stopped up dump line on the front.  If you have about 20 min to hold down the dump switch it finally goes back into the travel mode. 

John,

Most likely a dirt/mud dauber that has decided to build a nest in the vent hole.  It is hid behind a pressure switch on the manifold and those little devils can still find that vent.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."