Hi everyone...
As I've posted before, I'm going to be pulling my little 13ft Scamp trailer (that weighs 2200lbs but feels like 10000) on a trip out west in a few weeks. I've gotten the SSR wired up including electric brakes and 12v for the trailer, including relay circuits for the lights and back-up lights since the SSR wiring looked WAY too tiny for the job.
Last night I installed the AirLift1000 in-coil helper air bag system, #60779. I originally wanted the Firestone Ride-Rite/Coil-Rite version (#4106) but every single retailer I called across the country had none in stock; neither did Firestone-and Firestone had no idea when they would make some (i.e., import some from China). Good way to run a company. Anyhoo...
The installation was pretty straightforward, but was not very easy. Also, there was no way (for me at least) to install the air bags the way the manual says to. The kit comes with two toy-like plastic bags, two rubber spacers, and assorted tubing. The manual for the AirLift's states on the SSR you have to install the bags with the air valve to the top of the spring, with the spacer between the top of the bag and the coil spring seat. It also states you have to widen the existing hole in the factory rubber stopper at the top of the spring seat to 1". Looking at the truck from beneath, I see absolutely no reason in the world to do this, and the manual doesn't state WHY. However, if you are trying to install these with the vehicle on the ground and the coils still on the car, good luck installing them with the valve toward the top. The problem is that in order to insert the bags into the springs, you have to deflate them (by removing a cover on the valve, squeezing the air out and reapplying the cover), and work for about an hour screaming and cussing trying to get them in the coils. Once in, you remove the cap which was keeping them deflated, and the bags spring into shape. But, you then have to fathom a way to fish the tubing through the 1/4" of space between the top coil support and the truck body, down through the hole in the factory rubber stopper, while at the same time trying to figure out how to insert the giant rubber stopper that came with the AirLift's at the top of the bag, compress the bag, push the tubing over the valve stem in the top of the bag, and use pliers to slide the clamp on...all while all of this is INSIDE a coil spring. First of all, there is NO room at the top of the coils, second of all, neither your hand nor pliers will fit inside this tight spot at the top of the coil...once the bag and the stopper is there, you cannot push the bag down to even see the stem. This seemed impossible to me. Also, the factory support at the top of the coil spring is reasonably flat and smooth, minimizing damage to the bag...I saw little reason to have an additional rubber stopper up there. Now, the bottom has a big steel "hump" with a hole in it, and I can see the bags chaffing on it. So...
I checked the instructions for the Firestone bags, just to see the difference. Low and behold, their instructions state to insert the bags with the rubber stopper and valve stem at the BOTTOM, which made sense to me, and the only way to feasibly install them without removing the coils from the car. The bags seem pretty much identical, so I figured it didn't matter if you installed them with the valves/rubber stoppers on the top or bottom. It looked like I would have an easier time installing them at the bottom, along with the added benefit of keeping the raised section in the bottom spring seat from chaffing the bag by use of the rubber stopper. So, that's what I did.
I ran the tubing, which was simple enough. All of my trailer wiring...the plug, relays, ground, and now the air inlets for the AirLifts...are all mounted on the rear bumper support metal strip between the bumper and the battery tray. I didn't want to drill into anything major.
I installed mine, laying on the ground, without removing a wheel or even jacking the car up, which I'm sure made it a little more difficult. The hardest part was getting the bags IN the coils. The problem wasn't slipping the bag through the bottom of the coil, but the width of the compressed bag vs. the inner diameter of the spring. Jacking the car up wouldn't have even helped this aspect, and I was leary of jamming and pushing and pulling with my fingers in between coil springs on a jacked up car. But, after much thinking of "THIS WILL NEVER GO IN THERE!" I finally got the bags, with the valve toward the ground, in the coils. Now, here's the trick that I had to do. I still figured there was NO way to connect the tubing and fitting to the air bag valve once it was completely in the spring, due to lack of space combined with the tightness in the coil once the rubber stopper is inserted, let alone not a chance of getting pliers in there. So, this is what I did once I ran the tubing:
1) Took black plastic cover off of valve on air bag, pushed air out of bag, and reinstalled black plastic cover.
2) Got under vehicle, and started working, sliding, pushing, forcing, twisting, bending, contusing, and squishing the bag up the inside of the coil through the lower-most opening, screaming and cussing losing hope until about 2" of the bag was hanging out of the coil spring.
3) Once I had nearly all of the bag in, I pulled the black plastic valve cover off, letting the bag inflate.
4) I then made sure my tubing was exactly where I wanted it in regard to routing it safely away from the exhaust, through the hole/opening in the bottom of the coil spring support, fished through the rubber stopper that came with the AirLift's, and slid it on the valve on the bag that was hanging out of the coil spring.
5) I then tightened the clamp with pliers (slip-on type clamps) securing the tubing to the valve on the bag.
6) I then tried with all my might to shove the bag up the last 2" into the coil, now inflated. This was HARD.
7) Once the bag was pretty much all the way in the coil, I had to try to shove it up another inch to insert the rubber stopper, without compromising the valve and clamp. THIS would have been easier to jack the car up for more room, but I wasn't comfortable to do it due to safety reasons in my particular situation. After much prying and finesse, I was able to slide the rubber stopper in and make sure that the tubing/valve was positioned properly through the hole in the rubber stopper to prevent kinking.
8) Once the stoppers and bags were reasonably in proper shape with no kinks, I zip-tied the tubing, drilled my holes to mount both my air valves (you can use the supplied y-adapter as well to have only one air inlet valve) in my bumper bracket support, and made sure everything looked ready to inflate.
9) I inflated each bag to 35lbs, and they held air!

With all the squezing, bending, and twisting of the bags, I was concerned about the possibility of air leaks at the clamps. But, so far so good. The manual says they will lose some air over the first 24-48hrs. They seem to be holding reasonably well.
I haven't towed anything yet, but they definitely seem to have the ability to add some serious cargo carrying ability. The rear end can be jacked up a couple inches; it felt VERY weird driving around with the bags at 35psi; similar to an old Camaro with big Mickey Thompson's and airshocks. It FELT more jacked up in the rear than it looked...so I'm pretty hopeful that it will do its job pretty well regarding cargo carrying capacity and towing trailers to avoid rear end sagging.
I hope this helps anyone who wants to install these on their truck. It's pretty straightforward, and if you install with the tubing toward the ground, you will avoid a lot of headache. It can also be done without removing wheels, springs, or jacking the car up. I recommend them.
If you have any questions, PM me. I will let everyone know how they actually perform with a load in the back and/or while towing my little trailer.
Thanks for reading,
Jeff