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Old 10-04-2014, 05:32 PM   #1
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Air Bags, don't get the wrong ones - there are no right ones

A few weeks ago, a customer of ours stopped by my house to pick up some shocks for his Jeep. He was driving his 2013 Ford E250 RB 2wd van that we had recently done considerable suspension modifications to and added all the Aluminess goodies to.



He mentioned that he had air bags installed... "What?"

I explained the following, and he called me the next day, said he couldn't sleep and kept thinking about the air bags and wanted them removed. He had wondered why the ride had seem so harsh and didn't put 2 and 2 together until we talked.

I took a few pictures:





I removed the valve core from the schrader valve so there would be no air pressure or vacuum in the bag. This picture is at ride height. There is approximately 4.75 inches between the top and bottom metal mounts of the air bag.





I disconnected the lower air bag mount from the axle tube and used a Porta Power to compress the air bag until it bottomed out internally and started to lift the van. This represented the total available Bump Travel with the air bags installed - only 2.5 inches (4.75" at ride height - 2.25 fully compressed).





You can also see from the amount of shock travel (2 inches) that the bump travel was severely restricted. Normally this shock should cycle full stroke.






Next we jacked up the van from the frame, suspending the axle and tires in the air. You can see that the air bag acted as a limit strap and the axle was hanging from the air bag and not the shock and springs. The air bag manufacture specifically warns against allowing this as they are concerned about the life of the air bag - it is not designed to hold the weight of the axle, wheels and tires. Essentially there is only ~3 inches of droop from ride height and 5.5 inches of total travel because of the air bags.





Next I disconnected the lower air bag mount from the axle and allowed the axle to fully droop out to where it is limited by the springs and shock (we strive to time these together for maximum travel). You can clearly see how much additional droop was available.



I hope you will think twice before using air bags. They have their place, but...
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Old 10-04-2014, 06:10 PM   #2
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Re: Air Bags, don't get the wrong ones - there are no right

I agree 100% with above evaluation of the AirLift bags. Double convoluted bags are only slightly better. Ramsey may very well disagree with me here, but I found the Firestone Sportrite bags to be pretty decent, if you have to run airbags. For me, my payload may be anywhere from 0-5500 pounds, so some load Levelling is welcome. Also, the airbags improve my fully loaded ride by keeping the lower overloadeafs from engaging. These bags have about 10" of travel. Maybe a little more. The one on the left is the compressed relaxed height. It can compress more with weight. Likewise the extended one is probably a little longer when inflated.

Even these aren't perfect though. If the hardware fails and the plate shifts (happens ~ every 60,000 miles) or you don't have in-can controls and the air gets too low, they can get a pinch flat.
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Old 10-04-2014, 07:05 PM   #3
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Re: Air Bags, don't get the wrong ones - there are no right

Quote:
Originally Posted by carringb
For me, my payload may be anywhere from 0-5500 pounds, so some load Levelling is welcome. Also, the airbags improve my fully loaded ride by keeping the lower overloadeafs from engaging.
Widely varying loads is where air bags have their correct application. Proper selection and installation will minimize the negatives.

I see too many vans outfitted with air bags to correct a problem, that actually creates more problems, and could have been solved with correct measures in the first place.
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Old 10-05-2014, 12:57 AM   #4
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Air Bags, don't get the wrong ones - there are no right ones

Sounds like my van. Glad you convinced me to yank them.
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Old 10-05-2014, 05:10 AM   #5
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Re: Air Bags, don't get the wrong ones - there are no right

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Originally Posted by Ocsmb
Sounds like my van. Glad you convinced me to yank them.
You had the exact same thing going on.
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Old 10-21-2014, 12:39 AM   #6
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Re: Air Bags, don't get the wrong ones - there are no right

It would seem that a floating bag setup would eliminate most of these drawbacks. Are there other issues with such a setup? Or are they just rare for some other reason (new?)?
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Old 10-30-2014, 08:38 AM   #7
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Re: Air Bags, don't get the wrong ones - there are no right

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It would seem that a floating bag setup would eliminate most of these drawbacks. Are there other issues with such a setup? Or are they just rare for some other reason (new?)?
They do.

And I agree, bags like the setup pictured above are pretty bad! Too restrictive.
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Old 10-20-2015, 08:04 PM   #8
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Re: Air Bags, don't get the wrong ones - there are no right

Quote:
Originally Posted by MadScience
It would seem that a floating bag setup would eliminate most of these drawbacks. Are there other issues with such a setup? Or are they just rare for some other reason (new?)?
"Floating" setups eliminate the problem of limiting droop and acting as a limit strap - but I have still seen where they severely limit bump travel.

Before you bolt on any air bag, think long and hard about what is going to happen.
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Old 10-20-2015, 08:20 PM   #9
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Re: Air Bags, don't get the wrong ones - there are no right

Hi Ramsey. What kind of suspension modifications did you do to this 2wd? Is there any lift above stock height etc? Thank you
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Old 10-20-2015, 08:36 PM   #10
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Re: Air Bags, don't get the wrong ones - there are no right

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Originally Posted by wl1193
Hi Ramsey. What kind of suspension modifications did you do to this 2wd? Is there any lift above stock height etc? Thank you
Two plus inch lift in the front and rear - don't remember exactly as it was over a year ago. We match the lift, springs and shocks to the van so they are all a little different. It is running 33" BFG's so we also had to modify the sliding door.
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