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Topic: Leveling/leak after new air bags question for the collective (Read 788 times) previous topic - next topic

Leveling/leak after new air bags question for the collective

We had our (4) front air bags (looked very bad, no obvious leaks - yet but we were concerned ahead of this year's travel) replaced 4 weeks ago at FOT.  At the same time we had them check the remaining 6, both tag bags had minute leaks and were also replaced.  Drive axle 4 are still OK.

Since then we have had a constant leak down/lowering of the front of the coach.  FOT hasn't found the leak in their check and neither has Steve.  All the affected connections at the airbags have been checked, the original quick-connect fittings on each air line going to the air bags have now been replaced (the originals hadn't been replaced when the bags were done and Steve found several were then leaking) and that didn't solve the problem.  Steve checked the travel solenoids and replaced the o-rings on those since one looked questionable.  He also replaced those on the lower/exhaust solenoids as a precaution since an undetected leak there would cause this behavior.  We don't see  bubbles at the connectors anymore, the ride height valve, or anywhere on the six pack manifold that we can see.

The coach relevels about every 1 1/2-3 hours, initially squatting the back completely, followed by raising the front air bags (standard algorithm, lower first then raise the opposite when you can't lower anymore).  This is with the front starting at ride height (coach from travel mode) and leaking down.  This past weekend we also tried leveling from travel mode then shutting the leveling system off and the behavior didn't change.  I will say that in the 1 1/2-3 hours of the testing (measuring air bags every half hour), the "A" front tank pressure does not appear to go down (watching the Driver Information Center display).

Generally the driver side appears to be leaking down more (about 2x - 1.5 inches to the curbside .75 inch drop as measured between the plates of the air bags) but we aren't in a perfectly level site.  The front air bags generally measure within 1/4 inch (definitely 1/2 inch) side to side when freshly level, though. 

Thought I'd toss this out there to the forum collective to see if anyone has a thought.  Looking at our air diagram, if I read it correctly there are 2 air inputs to the front 6-pack; one from the A tank through the front regulator and one from the A tank through the front ride height valve, then each air bag has a single line from the six pack to the air bag.

Either we're missing a leak at or in one or more of the new front air bags or something else is going on (it could be coincidental with the new bags), but we're at the point we can't figure out what else to look at.  Very frustrating since prior to the new air bags, the coach would be rock-solid for a month or longer without needing to relevel.
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/leak after new air bags question for the collective

Reply #1 –
Would look at all connections that were associated with the bag R&R. Use the bubble mix for parties with a sprayer. Coach dropping that fast indicates an easy to find leak.

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

Re: Leveling/leak after new air bags question for the collective

Reply #2 –
Ours did the same thing after replacing the rear bags, and it was the connections. Once all were replaced with new ones, the problem disappeared. Maybe it's something with yours, even though you say they are all new?
1996 U295 36' WTBI

Re: Leveling/leak after new air bags question for the collective

Reply #3 –
Quote from: bogeygolfer –
Ours did the same thing after replacing the rear bags, and it was the connections. Once all were replaced with new ones, the problem disappeared. Maybe it's something with yours, even though you say they are all new?

We know at least 2 front fittings are definitely new.  They were replaced when Steve first started leak checking and found bubbles at them and had them replaced.  We were assured the other front and the tag fittings had been changed during the air bag installation (not sure why these 2 weren't). 

Quote from: Pierce & Gaylie Stewart –
Would look at all connections that were associated with the bag R&R. Use the bubble mix for parties with a sprayer. Coach dropping that fast indicates an easy to find leak.

Pierce, agree completely.  FOT did that 3 weeks ago and found nothing.  That's why Steve has continued to look for the problem (with soap) himself.
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/leak after new air bags question for the collective

Reply #4 –
Michelle, you and Steve know so much I figured my episode was already covered by what you wrote.  But since bogey had such, my problem came after new bags and took two trips back to get connections sealed.

I hope yours that simple but seems Steve already checked.  I was a bit perplexed....new air bags and that led to a problem I did not have before! 
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Leveling/leak after new air bags question for the collective

Reply #5 –
Michelle,
It sounds like you have confirmed that all connections associated with the air bag work are ok.
Sounds like the problem is the left front. When it leaks down it can drag the other side down a little due to the load on the other side.
I think I would eliminate the left travel solenoid by disconnecting the line from the six pack into the ride height control valve and put the end in soap water To see if air from the airbag is leaking through the travel solenoid.
John Duld
1995 U320C SE 40'

Re: Leveling/leak after new air bags question for the collective

Reply #6 –
Michelle & Steve,

Seems that your understanding of the air system is correct, so the leak has to be better isolated. How about a temporary shutoff on the air line from the 6-pack to a front pair of bags? Could a bag have a leaking seal or rubber hole?

Along with others our bags stayed tight for months, that is until we had our original bags replaced with new. Instead of being more secure, a new leak manifested itself after a week or so, which turned out to be at the re-used brass fittings.

When we had to cut off the hose end, it shortened our air line, so we had to cut some wire ties to route the air line a little differently so it will reach the new brass fitting.

You WILL find the leak. . .

Re: Leveling/leak after new air bags question for the collective

Reply #7 –
An update - Foretravel had us take the coach to the FT production team who have so far found one of the connections to the driver front forward bag was leaking bad enough to blow the bubbles off before you could see them.  The tech says he could actually feel the airflow once he saw what was happening.

The team is checking over the rest of the system as well.
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/leak after new air bags question for the collective

Reply #8 –
Michelle,

That's one of the big reasons I love the kid's party bubble solution. It makes bubbles that don't pop until they are huge. They are tough so don't get punctured if they hit on something.

Glad you found the problem. Good reminder for me as I have a couple of slow leaks I should get after.

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

Re: Leveling/leak after new air bags question for the collective

Reply #9 –
Quote from: Michelle –
was leaking bad enough to blow the bubbles off before you could see them.  The tech says he could actually feel the airflow once he saw what was happening.

The team is checking over the rest of the system as well.

            That's exactly what was happening with the leak I couldn't locate at the slide block regulator. The bubble soap was just blown out of the way of the escaping air. Ended up hearing it.

              Glad they have located your leak. ^.^d
Dean & Deirdre

2012 Arctic Fox 22GQ
Was 2003 U270