By Jspafford
The kit that is required is an airlift part# 59501. It can be ordered from many online companies or from most any trailer accessory store
Most of you Bronco II drivers are very aware of the sagging rear spring problem that plagues almost all of our beloved vehicles. Lots of guys install various springs and or leveling blocks to cure the problem. I added a set of helper springs, but when under a hard bump the spring would come up and contact the body. I decided to install a set of adjustable airbags. I can choose how firm or soft of a ride I want. If you wanted to get real fancy airlift makes a air compressor kit that will air up the bags from in the truck. Otherwise, they are aired up with a valve stem mounted in the location of your choice.
Open box and layout parts to verify all are accounted for.
1) First you need to know the normal ride height to adjust the springs accordingly. If the back is sagging badly jack up the body only until level and measure from the bottom of the rear wheel well to the center of the hub. Write this measurement down.
2) Raise the rear of the vehicle and place a jack stand under the axle just outside of the shock mount on both sides. Remove both rear tires.
3) Now that the truck is sitting full weight on the axle that is now sitting on jack stands, use your jack to raise the body of the truck up until you achieve normal ride height as noted above.
4) Place the bottom mounting bracket on the top of the leaf spring toward the front of the truck. Make sure the ear is hooked over the end of the spring perch plate. Use the U-bolt and hardware supplied to attach the bottom plate to the leaf spring.
5) Attach the white tool to the bottom plate and slide the top bracket over the top of the template tool. Now, adjust the black nut up or down so the top bracket lines up with the frame in a way so all the 4 bolts will not interfere with anything behind the frame rail.
6) Drill a pilot hole using the 4 holes in the bracket as a reference. Once you have the pilot holes drilled, remove the top bracket and installation tool before drilling the holes to 3/8″.
7) Once you have the 3/8” holes drilled, insert a black bolt through the bracket and frame, install a flat washer and locknut on the inside of the frame. Follow up by installing the remaining three bolts in the same order.
(NOTE) Be sure not to pinch any brake or fuel lines, also watch out for electrical wiring.
8) It is now time to position the airbag. First slide the top threaded collar of the airbag into the round hole in the top bracket. Next slide the bottom of the bag onto the bottom bracket. Use the course threaded bolt with washer and secure the bottom of the airbag to the bottom bracket.
9) Once the bottom is secure, thread on the black plastic nut around the top collar of the spring. Tighten slightly, as not to crack either the plastic nut of plastic threaded collar.
10) Thread the brass 90 degree airline fitting into the top of the airbag. Tighten hand tight followed up by the turn of a wrench. The fittings have thread sealer installed on them from the factory.
11) It is now time to route the airlines making sure to keep them away from moving parts or exhaust. I routed mine back through holes in the frame to under the rear bumper. In the kit they give two separate lines for each bag. I elected to put a “T” in the line right before the Schrader valve, thus eliminating the need to equalize each side, it fills them evenly.
12) The airlines just push into the fittings. Make sure the end of the tubing is cut straight and not crushed or distorted in any other way. It needs to be perfectly round to seal into the push in fitting.
13) Lastly, install the Schrader valve. I elected to install mine right above my 7-way Bargman plug. The bracket had enough empty space to do so.
14) The valve has a nut that is threaded on first; then slide the valve through the hole and install the outer nut to hold it in place.
15) Grab your air compressor and add some air. The back of the truck should lift almost immediately with as little as 5-psi of air. Fill it up to about 30-psi and check all the fittings for leaks. I found that I sit just over level running 50-psi in the bags.
16) Install tires and check for clearance around bags. Lower vehicle.
17) Enjoy the non sagging look, and now you can adjust your ride height and also adjust for various loads.
(I measured, the truck now has 3.5-inches of rear spring travel from no air up to 100-psi.)
