ruby on rails blog

When I tow my trailer, the rear of my 1998 ZJ likes to sag substantially. After doing some research, I discovered that a set of air bag helper springs would help raise the rear of the vehicle up while towing. Hopefully this will eliminate any sag and “porpoising” that would occur while I towed. I spent about $80 shipped for the Coil-Rite kit from Firestone (who may not make great tires, but apparently are the #1 air suspension manufacturer).

The kit includes a length of DOT air line, zip ties, two air bags, and misc bits and pieces. The installation took me about an hour, give our take. You will need a blunt object to help push the air bag inside of the suspension coils, more zip ties, a razor blade, and some scissors to cut the ties.

Jack up your Jeep, make sure you support it properly so you don’t kill yourself.
When I tow my trailer, the rear of my 1998 ZJ likes to sag substantially. After doing some research, I discovered that a set of air bag helper springs would help raise the rear of the vehicle up while towing. Hopefully this will eliminate any sag and “porpoising” that would occur while I towed. I spent about $80 shipped for the Coil-Rite kit from Firestone (who may not make great tires, but apparently are the #1 air suspension manufacturer).

The kit includes a length of DOT air line, zip ties, two air bags, and misc bits and pieces. The installation took me about an hour, give our take. You will need a blunt object to help push the air bag inside of the suspension coils, more zip ties, a razor blade, and some scissors to cut the ties.

As you can see, there is nothing inside of the coil. We will be wedging our air bags inside of these coils, then inflating them to help assist when towing.

1. The first step is to cut two sections of tubing, approximately 3″ long, each. After you have cut the tubing, insert the tubing into each of the two air bags. Start from one end of the air bag and roll them until they are are flat as humanly possible. You should also have two little nipple caps, take the caps and insert the pointy end into both lengths of tubing. This prevents the air bags from re-inflating themselves while you work on jamming them into the coils.

2. Insert the top of the air bag into the lowest rung of the coil, this is usually the one with the largest opening. Make SURE you insert the top of the air bag. The bottom of the air bag should be facing you with the tubing sticking out. Once you insert the coil, continue to use a blut tool to wedge, jam, or wiggle the air bag up into the coil. This is the most difficult part of the installation.

3. Once the air bag is inserted into the coil, straighten it out as best as possible. You can remove the tubing once the air bag is straightened out.

4. Run your air tubing, make sure you cut the tubing with a razor so it is as straight as possible. Scissors can deform the tubing, resulting in an air leak…trust me, I know from experience. Be sure to keep the tubing away from the exhaust and any places it might get “pinched”.

5. After you finish running your tubing, locate a spot on your vehicle where you want to mount the inflaction valves. I mounted them on the left, rear under my bumper.

6. Lower the vehicle and inflate the air bags slowly. Spray soapy water on the connectors and look and listen for leaks. Let the vehicle sit overnight at 35PSI, a few PSI drop is normal but anymore more is a good indicator of a leak.

That’s it! Make sure you run at least 5PSI minimum when you have these installed and check the air pressure monthly. Enjoy! Finally, if you found this tutorial helpful, consider buying it from Amazon using my referral ID! The price is actually $5 cheaper than what I paid!