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Installing air springs/bags from AirLift, and the accompanying compressor on a 2002 Avalanche.
[FONT=&quot]The goal of this procedure is to give the Avalanche a little stiffer support while towing our horse trailer. Here is the victim…err vehicle I will be installing them on.[/FONT] For starters, I'd like to suggest that this is not something you should just run into without having a plan. Since you've going to be running hoses, and wiring along the chasis of the vehicle it's a good idea to envision how you want it to work before you even block the wheels, or pick up a wrench. Drawing it out on a piece of paper works fine too.



First step is to make sure you have everything before you start. Lay out all of your parts, and verify against your parts list. This is also a good time to gather up the required tools


Now that you've got that all set, chock your wheels, and prep the vehicle for work. In addition to chocking the wheels, I also put it in 4 Wheel Low, mostly because I do not have a flat level surface to work on. (my driveway sucks) *Some of the other tools needed, but not pictured was an engine hoist, and a cordless drill, and ramps.
The installation manual suggested that installing the springs would be as easy as lifting the vehicle until the wheels came off the ground. It also suggested that removing the shocks would allow more travel. (Not nearly even enough, if you ask me.) I found that to make this as easy as possible to access the springs I had to remove the upper bolts of the sway bar links, remove the lower shock bolts, and one of the panhard rod/track bar bolts.

In the next picture you can see I started to remove the lower link bolt, only to realize that I would not be able to remove the link from the sway bar without fighting with it. Removing the upper is a much easier option.
 

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This is a shot of underneath the Avalanche with the shocks, sway bar links, and track bar disconnected. The driver's side spring removed.

Since I have the driveway from hell, I find it's a whole lot easier to use the creeper on cheap plywood sheets. ^^
To lift the vehicle you can use a jack, but I found it less scary to use my engine hoist to lift the rear of the truck at the bumper. A whole lot more secure than setting up a jack with a pole, or piece of wood as a spacer between the jack and the body.
Once the springs are out, you'll want to fit the air springs into the inside of the coils of the coil springs. The manufacturer suggests deflating, and rolling the air bags up, and fit them through the lowest coil opening. It takes some work, but in the end you get this:

The next step is to cut a larger opening in the rubber boot that sits on top of the coil spring as shown in the pic below.

Discard the small piece you cut out, as it will not be needed any longer. Since you already have your plan of how you want your hoses routed. (remember the golden rule, measure twice cut once) Measure, and cut your first length of hose, install spacers (if needed)
 

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Discussion Starter #3

For me this part was pretty easy, since my length of hose was long enough to be routed up into the body, while the spring sat on the ground. It would be fairly difficult to do, if you had to hold the spring up near it's home, while trying to feed the hose through tight spaces. This is where my hose had to feed through on the chassis.

Here's a shot of the spring, and air bag with hose routed through the top mount.

Since I wasn't trying to push my luck with lifting the body, I still had to apply some pressure to fit the springs back into place. The easiest way to accomplish this was to mount the lower rubber bushing onto it's home
 

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Discussion Starter #4 (Edited)
(Bushing, and mounting location shown for reference.)

Once this is in place, align the spring into the top mount, and be sure the hose is not being pinched, then while applying some pressure push the bottom of the spring upward while moving it onto the lower bushing.
After I installed the second spring, I then debated extensively where to put the air compressor, and finally found that behind the driver's side rear tire was a nice clean dry place to put the compressor. This goes back to plan this out carefully before you start. I had a plan, but it didn't work as well as I'd hoped, and I had no plan b going into the project, so I had to come up with it on the fly.

It was at this time, that the dark clouds started rolling in, and proceeded to downpour on me. It's a funny thing, after you're soaked, you don't mind the rain so much...lol Since it was raining, and I didn't have a secure place for my camera, this was the end of my pictures for this install.
The rest of the fun was spent running hoses, and wires. I wired the pump into the electrical center in the engine compartment. There were two unused oversized blade style fuse locations, once of which became the power tap for the compressor.

(The following pics were taken a week after the install)

 

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The Avalanche has a center console, and as such it has a lot of unused space under the cup holders. Conveniently the cup holders just pop out. Inside you will notice that there is a steel frame for the console, with a large circular cutout. Within that cutout, there is an opening in the carpet. It was so well hidden that I never checked for it, and sliced into the carpet anyway. I cut away a small piece of carpet, and insulation revealing the body pan. At this point I drilled a pilot hole, and then using a step drill bit, I opened up the hole. You need to be careful, as there is tubing running under this location. I believe this is the fuel lines. I fed the hoses, and positive lead for the compressor through this hole.

The compressor control panel was mounted along side the center console.

You can see in the picture below the springs are filled with about 30psi of air. The manufacturer states that a loss of 1-2psi over a 24 hour period is normal. So far we've seen about 1-2PSI loss over the course of the last week since I installed it, so I guess it's safe to say there are no leaks
 

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Beautiful job Patrick, WTG. This will be on my list of things to do for my project truck. Big help that you posted this. :great:

BTW can you take pictures of your knuckles for us. I would hardly believe that you got away without a mark :no:
 

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Actually because the Avalanche is so new, it was one of the easiest after market installs I've ever done. None of the bolts were frozen or rusted. The only damage I suffered was bumping my elbow into one of the carrots that hold the cladding in place near the air compressor. Gave myself a small slice, other than that it was smooth sailing.

In the pic of the compressor it's the one near the "G" in GMTruckClub logo.
 

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Actually because the Avalanche is so new, it was one of the easiest after market installs I've ever done. None of the bolts were frozen or rusted.
There's something you don't hear everyday!




The only damage I suffered was bumping my elbow into one of the carrots that hold the cladding in place near the air compressor. Gave myself a small slice.

In the pic of the compressor it's the one near the "G" in GMTruckClub logo.
Ouch! That's gonna leave a mark!:eek:uch:
 

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good job TraiLeadr! Did the ride get any rougher when you'r not towing? I would like to add helper bags onto my truck, but I don't want to get a rougher ride when I'm not towing. I also wonder if I can just use the regulator and use an existing compressor I hope to have by then on the truck. I'm trying to just run one air system on the truck (probably around 125PSI if I can pull it off) with a decent sized tank and reg all the output lines as neccesary for everything...
 

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You're my hero Patrick! This is something I will end up doing to my Silverado to increase tow capacity (or ride comfort and leveling while loaded) in the near future. Some day I may even ditch the hitch and go with a 5th wheel setup. My friend started his own transportation business with a hot shot trailer and a Silverado with a Duramax. I will just do it for recreational purposes. He installed airbags on his as well and tell me they are the shiznit!

Thanks for the step-by-step Patrick!:great:
 

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Did the ride get any rougher when you'r not towing? I would like to add helper bags onto my truck, but I don't want to get a rougher ride when I'm not towing. I also wonder if I can just use the regulator and use an existing compressor I hope to have by then on the truck. I'm trying to just run one air system on the truck (probably around 125PSI if I can pull it off) with a decent sized tank and reg all the output lines as neccesary for everything...
Actually the ride seemed to improve. It is a little more stiff, but it's not unbearable. My wife actually likes having the air in the springs, because it seemed to make the over all ride quality better.
I just get a kick out of pumping up the springs to about 35-40psi, and seeing the rake of the truck increase about 2-3 inches.

Air lift recommends not pumping the springs up more than 45psi (I think). If you're thinking about running upwards of 125psi, you're going to have one very stiff ride. It's going to feel like the flintstones car with rock tires. If you run over a pebble in the road, you're gonna feel it.

You could certainly just buy the springs, and run your own compressor, and regulator if you wanted. In fact the air spring kit comes with everything you need to setup the springs with an air stem that you can mount on the bumper for instance, and fill it from your home compressor, or a service station.

If you need to get the kind that fit inside the coil springs, then you need to monitor the air pressure. If it drops below 5psi, the bags chafe against the coils, and can wear a hole in them. To avoid this Air-lift sells a compressor with a switch that kicks in automatically when the pressure drops below 5psi. I didn't get the compressor kit with the switch so we need to watch the pressure. If I had known this before I bought the compressor I would have gotten the one with the switch, instead of being cheap, and not understanding the difference.


This is something I will end up doing to my Silverado to increase tow capacity (or ride comfort and leveling while loaded) in the near future. Some day I may even ditch the hitch and go with a 5th wheel setup. My friend started his own transportation business with a hot shot trailer and a Silverado with a Duramax. I will just do it for recreational purposes. He installed airbags on his as well and tell me they are the shiznit!

Thanks for the step-by-step Patrick!:great:
I would think you'll have an easier time than I did, if you got helper springs, since you don't need to drop the axle.
I would personally love to go with these for my suburban "Road Tamer", and lose the leaf springs.

Fifth wheel setup is a dream!
You have so much more control over a trailer with a fifth wheel. Not to mention you can see from the cab if you're inline with the trailer when hooking up. Not much need for a guide.
 

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Air lift recommends not pumping the springs up more than 45psi (I think). If you're thinking about running upwards of 125psi, you're going to have one very stiff ride. It's going to feel like the flintstones car with rock tires. If you run over a pebble in the road, you're gonna feel it.
I had every intention of regulating it down to the factory recommended air pressure. I'd just rather have one nice air system than have several little small ones. If all plans go well, with 125 PSI and a sufficient air tank, I could actually operate impact wrenches or other tools on the side of the road to change my tire...no tire iron wooo :yipi:

I would think you'll have an easier time than I did, if you got helper springs, since you don't need to drop the axle.
I would personally love to go with these for my suburban "Road Tamer", and lose the leaf springs.
I initially wanted to do that, but then I couldn't lift the truck, and I also don't want to think about how I would get the truck home if I blew a bag or a line. You can't exactly limp a blown bag home unless you had a tandem axle like the 18-wheelers do.
 

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Awesome! Great project. :great:
 

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Yeh, nicely done project Patrick. I do not believe I will have a need to do this in the near future but will keep it in mind. My boat is not heavy enough to bother the suspension on my 89 K2500, even though it is heavy enough to bother the tranny.
ANyhow, great job. I just wnat to tell you though I am a little concerned about the rust I see under your truck - especially for a 2002. I am from CT originally so I understand salt, but geez,you have some pretty good rust.
 

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I had every intention of regulating it down to the factory recommended air pressure. I'd just rather have one nice air system than have several little small ones. If all plans go well, with 125 PSI and a sufficient air tank, I could actually operate impact wrenches or other tools on the side of the road to change my tire...no tire iron wooo :yipi:



I initially wanted to do that, but then I couldn't lift the truck, and I also don't want to think about how I would get the truck home if I blew a bag or a line. You can't exactly limp a blown bag home unless you had a tandem axle like the 18-wheelers do.
That would be insanly awesome! Carrying your own air with you to run your impact wrenched!
 

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ANyhow, great job. I just want to tell you though I am a little concerned about the rust I see under your truck - especially for a 2002. I am from CT originally so I understand salt, but geez,you have some pretty good rust.
Yeah, I wasn't too thrilled about seeing that when I crawled under there. I don't remember seeing that much rust when we bought the truck two years ago. Not sure what happened there.

I'd love to be able to get it blasted, and then undercoated, but since it's the wife's daily driver it's tough to get my hands on for very long.
 
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