How to Install Air Bags on a 2007–2018 Silverado or Sierra 1500

This guide walks through fitting the BOSS rear air bag kit for the 2007–2018 Silverado and Sierra 1500 (BOSS LA-42). It follows BOSS's own fitting instructions, which are also on the product page as a PDF.

Always follow the instructions that come with your kit. This article is an overview to help you plan the job.

Before you start

• Check you have the right kit: the vehicle is printed on the instruction sheet.
• Raise the truck and support it on jack stands under the chassis rails, in front of the rear axle. Never work under a truck held up only by a jack.
• You'll need a 10 mm long socket for the bump stop, plus a basic socket set, cable ties, a sharp knife for the air line and soapy water for leak checks.

1. Assemble the air bags

Bolt the top and bottom end plates to the alloy rings on each bag, using the 6 bolts and spring washers at each end. Leave the bolts just loose enough that you can still twist the plates on the bag. You'll line them up during fitting.

2. Fit each bag

1. Remove the factory bump stop, using a 10 mm long socket up the middle.
2. Slide the bag assembly into place. The top bracket mounts against the old bump stop pad from the inside of the chassis, which keeps the bag away from the spring pack.
3. Fit the top U-bolt around the steel bump stop and into the top bracket, and tighten it.
4. Fit the bottom bracket so it clamps onto the factory bump stop pad on the axle, and tighten it.

3. Tighten the bag bolts

With the bags aligned, tighten the 6 bag bolts at each end, leaving a gap of about 1–2 mm between the two plates. Work evenly from one side of the plate to the other, the way you tighten wheel nuts, so the gap is even all the way around. Don't over-tighten: that can cause leaks.

4. Air line and valves

• Mount the Schrader valve panel somewhere easy to reach.
• Keep the air line at least 100 mm (4 in) from the exhaust.
• Cut the line clean and square with a sharp knife, with no burrs, and don't squash it.
• Push the line firmly into each fitting, then give it a short, sharp tug to make sure it's seated.
• Don't use thread tape, sealant, oil or grease on the line. It will cause a leak.
• Zip-tie the line to the chassis.

5. First fill and leak check

After fitting, inflate the bags to 80–100 psi once, then let them down to your normal pressure. This lets the alloy rings bite into the rubber and seal. Spray soapy water on every fitting: bubbles mean a leak. If a fitting leaks, pull the line out, rotate it and refit it, or re-cut it. If air leaks around the alloy ring, remove the 6 bag bolts and rotate the ring 90 degrees.

Finish by fitting the door decal in the door jamb.

Safety

• The bags help the truck sit level when it's legally loaded. Don't exceed the truck's GVWR.
• Never inflate the bags above 200 psi, and don't drive with them bottomed out.
• If you loosen any factory bolts such as U-bolts, retighten them to GM's torque specification, and replace U-bolts that look damaged.

Need the kit? BOSS rear air bag kit for the 2007–2018 Silverado and Sierra 1500. Other years: Chevrolet and GMC kits. BOSS also posts installation videos on youtube.com/bossairbagsuspension.