Rolling lobe air bag effective travel?

Brian Diehl · February 07, 2015, 09:02:41 AM

I'm getting closer to installing my leveling system. One question I have is what the effective travel distance of the MC9/96A3 rolling lobe air bag is. What is the safe travel distance from un-inflated to fully inflated? Hopefully someone knows this?

Thanks.

gumpy · February 07, 2015, 09:12:18 AM

I get about 3 inches in either direction on mine. In my opinion, it's not really worth the hassle and I'd probably look for Big Foot levelers or something like that if I were doing it again.
You still have to have the bus pretty level for air bag leveling to be effective, and even small leaks will cause you to be out of level by morning.

It's not really about travel limits. It's more about pressure limits. You should regulate the maximum pressure that can be applied to the bags. I believe I have mine set at 80 or 90 psi.
The bags cannot be over extended if their are not allowed to be over inflated.

Send me an email or call if you want to talk about it.

craig

Brian Diehl · February 07, 2015, 10:07:47 AM

Thanks Craig. I thought 6" was about the travel limit on the bags. I'm going to be using linear actuators with feedback to control my level side to side level. Fore to rear leveling is not as important to us. If this works well side to side I'll add an additional linear actuator on the front to help with fore to aft. Many state parks are close to level, but just enough off that a little side to side control will be nice.

Thanks for the information.

Lin · February 07, 2015, 10:14:25 AM

The distance from uninflated to to fully inflated on my regular air bags is about 6 inches. This means that air bag leveling can only give you about 6 inches difference from rear to front axel at most. However, since you are more concerned with side to side, 6 inches goes a long way to getting you level.

We use a combination of air bag leveling and blocks. Being able to use 6 inches less blocks fore to aft does make things a little easier too. Our system just uses some push/pull cables, so it was cheap and easy.

Fredward · February 09, 2015, 11:52:50 AM

Hey Brian,
That's how I've been thinking of doing leveling also. Have you found a linear actuator that will fit and be weather proof? I was thinking I would replace the OEM piece that goes from the axle to the ride height valve. I haven't found anything that met those requirements yet.
Fred

Brian Diehl · February 09, 2015, 05:32:21 PM

I am thinking about using these:
http://www.firgelliauto.com/products/feedback-rod-actuator

or maybe these:
https://www.pololu.com/product/2307/pictures

The 6" stroke model would be almost an exact match to the existing links between the axle and the leveling valve. I was thinking I would mount this upside down as the actuator and position sensing ends are protected by gaskets. This would also limit the amount of wire moving freely in space.

Fredward · February 10, 2015, 04:22:17 AM

Yes that's the type I was looking as well. I like the integrated potentiometer which could provide position indication. The other concern I have is the vibration. Imagine the amount of shaking that device will be subjected to when driving down the road.
FT

TomC · February 10, 2015, 07:59:41 AM

Having air suspension leveling system is unbelievably convenient. I kept the automatic leveling valves-one in front and two in back. I can over ride them and manually level my bus. If I'm parked on a highly crowned road, I can level my bus just about level-looks weird, but works. Also, if just staying overnight, it takes less than a minute to level the bus when stopped for the night.
Don't worry about the travel-can be around 6 or 7 inches. If you deflate the suspension, the bags come down to rest on either the interior rubber bumpers in the air bags, or the rubber bumpers on the axle. If you over inflate the bags, the over extension will be stopped by the shock absorbers. Good Luck, TomC

solodon · February 10, 2015, 08:43:32 AM

Something that comes to mind as I read the specs for the units. There could be a problem if the units were installed in a manner that the fully retracted setting is at a point where the chassis isn't on the bump stops first. This could apply pressure on the acutator in excess of the amount it can take. Be sure the chassis can rest on the bump stops when the bags are fully deflated. I could be wrong as it's happened before and too frequently. Don