null
Skip to main content

Rear Air bag Tow Assist Kit FO-G1102

FO-G1102

2001-2010 4x2 / 4x4 Chevy/GMC 2500/3500 including HD Load Assist Install instructions

Be sure to take all applicable safety precautions during the install of this kit!! The following instructions show the left, driver’s, side of the vehicle. To install the right side simply follow the same procedure for the other side.

Air helper springs flex and expand during operation, make sure there is plenty of clearance in all ranges of operation against rubbing against any parts of the vehicle.

For your safety and to prevent potential damage to your vehicle, DO NOT exceed the maximum load recommended by the vehicle’s manufacturer (GVWR).

The air springs are rated at a max 150psi, this pressure may allow you to carry a load greater than the vehicle is capable of handling. It is in your best interest to have the vehicle weighed once it is completely loaded and compare the loaded weight to the max allowed by the manufacturer. Check your owner’s manual or data plate in the driver’s door jamb for max loads allowed per your vehicle.

While inflating the air springs, add air in small amounts, frequently checking pressure. The air springs require much less air volume to reach capacity and will inflate quite quickly.

MINIMUM PRESSURE- 5psi

NORMAL PRESSURE- LIGHT LOAD- 60-80psi

MAX PRESSURE- HEAVY LOAD- <150psi

BURST PRESSURE- 550psi

CAUTION- WHEN CUTTING OR TRIMMING AIR LINE, ONLY USE A HOSE CUTTER, RAZOR BLADE, OR SHARP KNIFE. A SHARP SQUARE CLEAN CUT IS REQUIRED TO ENSURE A LEAK FREE AIR SYSTEM. YOU CANNOT USE WIRE CUTTERS OR SCISSORS, AS THESE TOOLS FLATTEN/CRIMP THE AIR LINE AND WILL CAUSE A LEAK IN THE FITTING.

GUIDELINES FOR ADDING AIR

  1. Start with vehicle level or slightly above level
  2. When in doubt, always add air.
  3. If the vehicle dives while braking, increase the pressure in the front bags (if equipped)
  4. If you ever suspect the air bags have bottomed out, increase the air pressure.
  5. Adjust the pressure up and down to find the best ride quality.
  6. It may be necessary to maintain different pressures on each side of the vehicle. Loads such as water, fuel, and appliances will cause the vehicle to be heavier on one side. Variances as much as 50psi is not uncommon.

FOLLOWING STEP WILL IMPOROVE LOGEVITY OF YOUR AIR SPRINGS

  1. Check air pressures weekly.
  2. Always maintain a normal ride height.
  3. If the system develops a leak, use a soapy water solution, address the leak immediately.
  4. When increasing load, always adjust the air pressure to maintain a normal ride height. Increase or decrease pressure from the system needed to attain normal ride height for optimal ride and handling characteristics. Remember loads carried behind the axle, including tongue loads, require more leveling force/pressure than those carried over the axle.

ASSEMBLING THE AIR SPRING AND BRACKETS

  1. Add thread sealant to the 90 ° elbow fitting and install to the top of the air spring. It may not thread completely into the bag, which is fine since the threads are tapered to do this specifically.
  2. Install the upper bracket onto the air spring using the supplied nuts and washers.
  3. Insert two of the 3/8” carriage bolts through the large holes and they will seat into the square holes of the legs in the lower brackets. NOTE: Driver’s side only- Insert 6mm x 25mm bolt into small hole on the lower bracket before attaching the lower bracket to the air spring assembly. 2500HD MODELS ONLY: Install a 3/8” bolt and lock nut through the hole in the lower bracket with the head of the bolt facing down. Tighten down securely.
  4. Attach the lower bracket to the bottom of the air spring using the tapered Allen screws. Tighten securely.
  5. Jack up the rear of the vehicle and support the frame with jack stands. Drop the axle to gain clearance to install the air spring and bracket assemblies.
  6. Remove both OEM bump stops/jounce bumpers under the frame rail and save or discard properly. NOTE ON 2500HD MODELS ONLY: the driver’s side axle may have a small braket with a nut that has nothing attached to it. This bracket must be trimmed off of the axle in order to install the assembly correctly.
  7. The elbow fitting points towards the rear of the vehicle on the driver’s side and towards the front on the passenger’s side. Insert two 3/8” bolts and flat washers through the existing bump stop/jounce bumper holes and through the slotted holes in the upper bracket. It may be helpful to raise the axle at this time so that the upper bracket reaches the frame . attach the upper bracket using two flat washers and nyloc nuts on each previously installed 3/8” bolt. Push the bracket towards the center of the vehicle and tighten the bolts and nuts up to the point where you can still slide bracket around.
  8. Bring the axle all the way up and remove jack stands supporting the frame. The upper bracket is slotted for forward and backward adjustments. The bottom adjusts by moving the bracket on the axle in and out.
  9. Adjust assembly so that the air spring is perpendicular to the bottom and top mounting brackets. Then tighten the top mounting bolts to 20lb/ft
  10. Attach the curved axle strps to both lower bracket carriage bolts using flat washers and nyloc nuts. IMPORTANT TO TIGHTEN EVENLY TO 16lbs/ft
  11. Attach the brake line bracket to the lower bracket using the previously installed M6 x 25mm and nyloc nut. Attach the brake line clip onto the emergency brake line bracket. Alighn the brake line and clip assembly so that the two do not bind the cable and are not in a position to come in contact with the air spring. Tighen all associated hardware securely.