Rear Coil Air Bags Questions

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Jan 6, 2014
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446
Location
Spoakne Valley, WA
 
So I knew my stock bump stops were gone so I ordered some Daystars but I also ordered some air bags for the rear.

I though I knew my cruiser well, but when I looked under to spray Penetrating oil I saw in the coils there was bump stops.... were those always there AKA factory? I put the lift on 6 years ago and dont remember. Can I still put air bags in under those or do they need to come out? I searched around but didn't see many other threads with pictures :hillbilly:

OME 2.5 lift and Mad Dog shocks
Links to Bags and Bumps

EDIT: the bump stops listed above do not fit stock holes. Ordering these to try Smaller Bump Stops

IMG_20200214_141833.jpg
 
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Joined
Nov 9, 2012
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Location
Olathe, KS, USA
 
So I knew my stock bump stops were gone so I ordered some Daystars but I also ordered some air bags for the rear.

I though I knew my cruiser well, but when I looked under to spray Penetrating oil I saw in the coils there was bump stops.... were those always there AKA factory? I put the lift on 6 years ago and dont remember. Can I still put air bags in under those or do they need to come out? I searched around but didn't see many other threads with pictures :hillbilly:

OME 2.5 lift and Mad Dog shocks
Links to Bags and Bumps

View attachment 2210985
Spray your penetrating oil in through the hole in the frame. That's where the threads are.......
 
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Aug 26, 2009
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5,606
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flat earth Midwest
 
 
In addition to removal of the bump stops inside the coil, on the Airlifts (at least) you'lll need to cut a hole in the coil spring base to accommodate the air line that goes to the bottom of the bag. Under 3 hours on my install and I'm a slow old guy.

Airbags are probably the most bang for the buck of all the <$100 mods. With the minimum air (5 lb with the Airlifts) in them, they improve the ride. Add more air and it really helps for those situations where you need to carry a heavier load from time to time. They helped a lot towing our trailer on vacation, for instance.
 

bajaphile

Boojum Hugger
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On my truck there were already holes on the bottom coil bucket. I used a step drill bit to open it up. You'll need to do this otherwise the air line will rub and fail quickly. I've had my air line rub off the barb a couple times but it is easy enough to trim off and re-attach (don't need to remove anything, just crawl under and in a few mins they are good again).

Also it is important to buy the stock length bags, even with a lift. The coil air bags work by pressing outwards on the coil, not similar to a leaf spring bag. If the bag is too long you'll just limit articulation, as the suspension will try to collapse the bag which is not what it is meant to do.
 
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flat earth Midwest
 
 
Will the air bag tear at full droop?
I doubt it and the design suggests that isn't an issue. The bag is sized for the specific application, so fit is good from looking at it in the install. The airline comes in at the bottom and nothing else ties it in any way. It sits at the bottom of the coil inner space, although there is not too much free space on top...But nothing to hold it to tear at full extension.

As was mentioned, the hole to let in the airline needs to be large and smooth enough not to snag and make a leak.
 
Joined
Jan 14, 2012
Messages
390
Location
Sacramento, CA
 
Forgot to mention, rather then taking a step bit and drilling the spring perch out for the airline, you might as well hit it with a punch in the center and drill to the recommended 3/4 I believe. The hole that’s already there will still be far from center and the line will most likely pinch. I took an air grinder to it after the fact instead.
 
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Jan 14, 2012
Messages
390
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Sacramento, CA
 
Which model # bag did you use? Thanks.
60755 to compensate for the lift. 60728 is the kit for stock height.

Per airlift, 1” gap is required before inflation. The bags don’t really push upward rather they push outward and support the coils.

EDIT: 1” gap from top to bottom, not side to side.
 
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bajaphile

Boojum Hugger
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You really only need the stock AirLift bag PN, even with a 4" lift. If you go too tall, it will limit articulation. The bag is not meant to be loaded like a leaf spring bag. It will crush and most likely pop with any off camber offroading. This is why people have had problems with them in the past. I've had mine for a few years now and run a 4" lift and stock bags with good success. As you mentioned, they work by pushing outwards to fill the pitch of the coils. You want to have a large gap between the frame bucket and the top of the bag.
 
Joined
Jan 14, 2012
Messages
390
Location
Sacramento, CA
 
You really only need the stock AirLift bag PN, even with a 4" lift. If you go too tall, it will limit articulation. The bag is not meant to be loaded like a leaf spring bag. It will crush and most likely pop with any off camber offroading. This is why people have had problems with them in the past. I've had mine for a few years now and run a 4" lift and stock bags with good success. As you mentioned, they work by pushing outwards to fill the pitch of the coils. You want to have a large gap between the frame bucket and the top of the bag.
We’ll she how she does when we go play in the rocks. I’m sure I could get more but my thought process was:

I see wheels and tires off from removing an axel...just finished working on truck...let’s try things out.

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Apr 9, 2013
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I'm not an expert on this topic, but I spoke to AirLift CS a few times before I bought and installed bags on my 80. What I recall them saying, and what I did, was buy longer bags than for stock springs. I have a TJM 2.5" lift. What CS told me was to have 1" of space above the bag with no load and 5# in the bag.
While I agree that the bag works by lateral expansion, it seems that we would want as much vertical height in the spring to be supported by the bag as possible. I've wheeled my truck pretty hard with the bags, with no problems.
If you have a lift, I suggest calling AirLift and chatting with them before you order. I found their reps to be well informed and friendly.
YMMV.
 

80t0ylc

Hill & Gully Rider
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Sep 24, 2008
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Canyon City, OR
 
 
You really only need the stock AirLift bag PN, even with a 4" lift. If you go too tall, it will limit articulation. The bag is not meant to be loaded like a leaf spring bag. It will crush and most likely pop with any off camber offroading. This is why people have had problems with them in the past. I've had mine for a few years now and run a 4" lift and stock bags with good success. As you mentioned, they work by pushing outwards to fill the pitch of the coils. You want to have a large gap between the frame bucket and the top of the bag.
I'm running the OME 2.5" lift and have the stock bags ( 60728 ) ordered and agree with your logic - it makes sense. But, I've seen 3 owners that use different bags with their lift. @Sc0- , @bicycleagent003 , & @dsmud4u
We’ll she how she does when we go play in the rocks. I’m sure I could get more but my thought process was:

I see wheels and tires off from removing an axel...just finished working on truck...let’s try things out.....
No disrespect intended, but your poser shots don't help much......You never posted the results of your playing in the rocks. How'd it go?
 
Joined
Jan 14, 2012
Messages
390
Location
Sacramento, CA
 
I'm running the OME 2.5" lift and have the stock bags ( 60728 ) ordered and agree with your logic - it makes sense. But, I've seen 3 owners that use different bags with their lift. @Sc0- , @bicycleagent003 , & @dsmud4u
No disrespect intended, but your poser shots don't help much......You never posted the results of your playing in the rocks. How'd it go?
No worries, still working out some kinks and ordered some metal tech rock sliders. I was planning on going to holister hills recently but I’m activated to assist at a food bank in San Jose. Let’s just say the protest going on are compounding the already dire situation of OHV areas closed.

I will report back with results as soon as I can.
 
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