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Anyone know how rear air bags work

luberhill
Explorer
Explorer
The PO has installed rubber air bags over the rear springs, there is a valve stem for both.
What’s the purpose ? How much air do I put in ? Right now they are not touching anything
Thank you
2013 Winnebago Sunstar 26HE
16 REPLIES 16

Jack_Spratt
Explorer
Explorer
50# on each side on my E450 class c
Leprechaun 260 DSF
2017 Big Horn FL3750

'10 Yellow Lab to keep us on our toes.

garyhaupt
Explorer
Explorer
You have to fill yours manually...there is an option. One I took. Mine too, came with valve stems. Still there. I had the air bag compressor installed. Gauge on the plastic stuff under the dash with the control buttons..one on each side. Looks down right spiffy..plus, I don't have to stand out in the weather to check and fill..and I can do it as roll.

https://www.google.com/search?client=firefox-b-d&q=air+bag+compressor


Gary Haupt
I have a Blog..about stuff, some of which is RV'ing.

http://mrgwh.blogspot.ca/

DrewE
Explorer
Explorer
With my class C, I find about 40 psi works out best for the air helper springs.

If they're Firestone ride-rite units, you're supposed to have I think a minimum of 10 or 15 psi, and no more than 90 psi. The volume of air requied is qutie small; a bicycle hand pump is easily able to adjust them as needed, while a large compressor can be a bit too fast if you're not careful. Even checking the pressure with a standard tire gauge can lower it a half pond or a pound, which is sometimes handy for fine-tuning if you care about that level of (probably unnecessary) precision.

It should be pretty obvious what works reasonably well when driving around. Too little, and you'll feel rather like it's wallowing around on bumps and dips; too much, and you're driving on rocks. You can also gauge by ride height (which is what they intend, really), but it's really really hard to get a pre-load ride height for a motorhome since the majority of the load is bolted or welded to the chassis before you get it.

Grit_dog
Nomad III
Nomad III
Typically air bags are fixed top and bottom and don't float, so not sure what you got going on under your Winnebago.
However, the PO likely installed them because they thought it was overloaded or too soft of rear suspension.
You say it's not sagging, which in general, means you don't need anything to help the suspension.
Why not drive it no air, then 20psi, then 40 psi or whatever and see what feels best?
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

RollandB
Explorer
Explorer
I put air bags on my previous truck to level the ride when towing. Had a fill for each side if I ever needed them different.

My current truck came with Timbrens which I prefer to the bags. No harsh ride when empty and no baby sitting the pressure in the bags.
2013 Yukon

2021 Coachmen Spirit 1943RB

ZINGERLITE
Explorer
Explorer
Optimistic Paranoid wrote:
Generally speaking, with airbags, if there is only ONE air fitting to feed both bags, when you go around curves, and the motor home leans, it will force air from one of the bags over to the other side. A lot of people feel it's better that each bag has it's own separate air line. In addition to preventing this, it allows you to put more air into one side or the other to adjust for side-to-side weight differences.

BTW, is there air in them now? How much? Is your motor home level?


That's the best way. I've got a slammed project truck with air ride suspension and each bag has separate valves for this exact reason.

djfrown
Explorer
Explorer
I have a 2010 GMC 2500HD 6.0L that I tow a Koala 26Qi with that has air bags and auto-sensing Bilsteins front shocks. I use ~15 psi when empty and ~45 when towing. The ride is smooth.

badsix
Explorer
Explorer
I have a 2010 GMC that I tow a 27 T/T, with it hooked up ready to go with water the truck is almost and inch low in the back. I air up my bags with about 15- 18 psi just to were the truck starts to raise about 1/2 - 3/4 inch. it makes the ride so much better, stops a lot of the porpoise effect.
Jay D.

doxiemom11
Explorer II
Explorer II
Previous had rear air bags on a GMC Envoy. It had it's own built-in-compressor and automatically adjusted the ride height based on the load in the rear-end. There was a valve on the airbag, but we didn't have to do anything with the valve or put air in/out.

luberhill
Explorer
Explorer
Optimistic Paranoid wrote:
Generally speaking, with airbags, if there is only ONE air fitting to feed both bags, when you go around curves, and the motor home leans, it will force air from one of the bags over to the other side. A lot of people feel it's better that each bag has it's own separate air line. In addition to preventing this, it allows you to put more air into one side or the other to adjust for side-to-side weight differences.

BTW, is there air in them now? How much? Is your motor home level?

There is two separate valves
Don’t think there is air now they are not touching the springs, it is level
2013 Winnebago Sunstar 26HE

Cummins12V98
Explorer III
Explorer III
jkwilson wrote:
Generally you adjust the pressure to restore ride height to normal after applying a load to the vehicle such as hooking up a trailer.

You need to find out what kind you have. Some require a minimum pressure to avoid damage.


Please tell what is "normal" ?
2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

Optimistic_Para
Explorer
Explorer
Generally speaking, with airbags, if there is only ONE air fitting to feed both bags, when you go around curves, and the motor home leans, it will force air from one of the bags over to the other side. A lot of people feel it's better that each bag has it's own separate air line. In addition to preventing this, it allows you to put more air into one side or the other to adjust for side-to-side weight differences.

BTW, is there air in them now? How much? Is your motor home level?

luberhill
Explorer
Explorer
Old-Biscuit wrote:
If might help if you would post Year/Make/Model of truck

It’s a 2013 Winnebago 26he Sunstar But they didn’t come on it
2013 Winnebago Sunstar 26HE

theoldwizard1
Explorer
Explorer
40+ years years ago my Dad had some on an old full sized Mercury (what a "boat" !). They worked great ! He had extension hoses that went out to the sides. The only issues was they recommended that you fill them BEFORE you placed a load on the vehicle. After loading, excess air was removed to get the ride height back to normal.