Rear Coil Air Bags Questions

[bajaphile]

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

Yep, when I was researching, I saw a lot of guys using longer bags. There also were a lot who were reporting failures, but I do not recall if there was a direct correlation between the length of bag or not. I think I am going on 3 years with the AirLift bags and have not felt any impacts on articulation, or have any issues..

 

[dsmud4u]

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.

Just out of curiosity, how big of trailer were you pulling?

 

[dsmud4u]

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?

Still haven’t done anything crazy but articulation does not seem terrible. I went to Hollister hills a month ago and I experienced no real issues.

 

[80t0ylc]

Still haven’t done anything crazy but articulation does not seem terrible. I went to Hollister hills a month ago and I experienced no real issues......

That's good news. I don't "play in the rocks", but do from time to time encounter some rough stuff in overlanding. Had mine installed for roughly 1.5 months now with one overlanding trip. They've definitely helped my rear droop with aux tank & trailer tongue weight. Passenger side developed a leak which turned out to be the hose joint at the schrader valve - easily fixed. Hope to have the same performance for years to come.

 

[greentruck]

Just out of curiosity, how big of trailer were you pulling?

It's the M101 CDN in my sig line. Probably a good 1500 lb or so when loaded up for camping.

 

[80t0ylc]

I've been concerned about running the stock suspension bags in my OME 2.5" lift. This post recommened it:

.....................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.

And then again:

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.

However, this post got me to thinking. If the manufacturer was suggesting longer bags, it must be important or at least give you pause to think:

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.

So I crawled under and looked at the top of the bags. These 2 pics are with a full 24 gallon aux fuel tank with no trailer tongue weight or additional camping gear and 10 lbs psi.....
Passenger's side:

Driver's side:

The tops of the bags are touching the top spring perch - I can't get my fingers in between bag and perch. The shape of the bags prevents contact with the last available coil, at least at 10# psi. I can't see that a longer bag is needed for my 2.5" lift. Maybe with a taller lift like a 4" or 6", but for the shorter lifts IMHO, I think the stock bags should be sufficient. Just wanted to share this and put it out there for debate.

Edit: I should also note that bottom of bags are resting on bottom spring perch, so the bags contact both top & bottom perches as well as the coils.

 

[dsmud4u]

Slightly off topic but does anyone have any experience with airbag man?

I heard you can run up 60psi or so with the sleeves over their bags and wondering if that directly translates to higher weight carrying capacity?

 

[80t0ylc]

Slightly off topic but does anyone have any experience with airbag man?

I heard you can run up 60psi or so with the sleeves over their bags and wondering if that directly translates to higher weight carrying capacity?

No, but from your post, I Googled and checked them out and out of curiosity requested a quote for their kit (which is for 75 mm lift):
CR5052 Air Suspension Helper Kit for Coil Springs

since I'm running a 2.5" lift. They're out of Australia but looks like they use Firestone air bags which are a quality product. I'm using them on my F350, but it's a leaf spring coil kit.

Edit: Crap, I just noticed what I really need is the HP kit, so I also requested a quote for the CR5052HP

 

[80t0ylc]

Slightly off topic but does anyone have any experience with airbag man?

I heard you can run up 60psi or so with the sleeves over their bags and wondering if that directly translates to higher weight carrying capacity?

I got a quote back last week and just had not posted it. It was for the CR5052 with out the protective sleeves. The reps seem helpful and suggested I could save some on shipping costs: "International Post drops the freight charge to around $60.00AUD but you will find it is a longer shipping time." Prices shown are AUD.

 

[dsmud4u]

I got a quote back last week and just had not posted it. It was for the CR5052 with out the protective sleeves. The reps seem helpful and suggested I could save some on shipping costs: "International Post drops the freight charge to around $60.00AUD but you will find it is a longer shipping time." Prices shown are AUD.

I might consider them in the future. I believe ultimately I need to move to heavier spring.

I still like the idea of running an airbag, just so I can stiffen when I’d like to but not have the rear at full stiff all the time. Thanks

 

[greentruck]

I might consider them in the future. I believe ultimately I need to move to heavier spring.

I still like the idea of running an airbag, just so I can stiffen when I’d like to but not have the rear at full stiff all the time. Thanks

Coil springs vary a lot in height depending on the load on them relative to leaf springs, torsion bars, etc. Depending on your needs, if you stick with coils only and have widely varying amounts of weight carried aboard, then you'll likely be unhappy at least part of the time. With airbags, they allow you to dial in a ride height and carrying capacity that tends to overcome the tendency of the coils to not be optimal for all conditions. They'll let you run the coil that best suits your needs and compensate when it's not optimal. You can have the loaded capacity you need, while running a coil that gives you better performance for daily and trail needs.

 

[cnorm5623]

Well, I didn't pay attention to how far this thread got! Well less than a year later and I went to air up my bags to pull a trailer and they both wont hold air. I need to get it up on my brothers lift and see where my problem is. tubing or bags.

 

[greentruck]

Well, I didn't pay attention to how far this thread got! Well less than a year later and I went to air up my bags to pull a trailer and they both wont hold air. I need to get it up on my brothers lift and see where my problem is. tubing or bags.

A line to each individually or are they plumbed together?

I think AirLift recommends checking them monthly. I did that the first few months after I had a small leak on my initial install. I needed to tweek a connection or something minor IIRC. I'm not so disciplined now that the install has held up, but do check them every couple of months.

 

[dsmud4u]

Well, I didn't pay attention to how far this thread got! Well less than a year later and I went to air up my bags to pull a trailer and they both wont hold air. I need to get it up on my brothers lift and see where my problem is. tubing or bags.

It’s likely your air bag nipple to the hose. If the spring perch is not hogged out enough, with articulation the bags will move with the spring and May not sit properly. You will wind up with a chaffed line or clamp that’s not holding anymore.

 

[80t0ylc]

Well, I didn't pay attention to how far this thread got! Well less than a year later and I went to air up my bags to pull a trailer and they both wont hold air. I need to get it up on my brothers lift and see where my problem is. tubing or bags.

Air Lift's suggestion to use soapy water works great to find your leak. Helped to find mine quick. Mixed a squirt of Dawn dish detergent in a spray bottle of water. Spray on your connections - it'll even reveal slow leaks. Just need patience to watch for bubbles to form.

 

[cnorm5623]

Good news, hoses just pulled off the barbed fittings on the bottom of the bags. I think I pulled them too tight when running the lines. I will come up with something better.
I did spray them with soapy water too to make sure there was no other leaks! Thanks for the advice all.