Mounting the Air Compressor and Tank

Mounting the air tank and compressor was as easy as finding the right spot in the small open area opposite the muffler. Even so, it's still a game of trial and error. Access to an auto lift would have been a nice amenity, but my dad's Bone creeper and some large floor jacks made the job tolerable. I positioned the compressor as shown in the photos, with two of its "feet" bolted to a lip in the frame cross member and the other two feet on a steel plate I made from the pile of scrap metal at my disposal. Another piece of steel plate was cantilevered out from the underside of the cross member to support the plate. This required basic metal fabrication, plenty of measuring for drilling bolt holes, and a good drill for securing sheet metal bolts to the frame. While metal fabrication might sound intimidating for anyone who hasn't done it, the drill press and band saw made it easy. All my cuts were pretty much square, no welding was needed, and the end result was a very solidly mounted compressor. The angle of the support plate is somewhat odd partly because of the shape of the frame - not so much flat and straight - which put limits on where the plate could be mounted flush. Also, I needed to avoid the torsion bar bolt. And then there's the laziness factor - a couple existing holes in those particular pieces of steel just happened to line up pretty well at that particular angle.

Next up was the air tank. I had to stray from what is probably the recommended mounting for the tank because of two factors: 1) the frame bowed outward within the space I had to work with, making a direct flush mount impossible and 2) the rear brake lines were routed along the inside of the frame. I really didn't want to disturb the brake lines, so I worked around them. As I mentioned, the goal was to mount the tank as high up under the frame as possible, which meant rotating the tank 90 degrees. With this, I needed to fabricate some more metal supports that would hold the tank on its side, as close to the frame as possible. The photos below show how I did this - the front side of the tank support bracket sits flush against the frame. The rear support bracket has a couple-inch gap between the frame. Here again, the shape of the underside of the frame didn't allow for flush mounting of a support plate directly across from the tank's rear bracket, due to the frame's curvature as it extends toward the rear axle. As with the compressor support plate, I had to go at it from an angle, using angle iron to get some extra strength for the length I had to cover. The angle iron reduces clearance under the frame by an inch or so, but it's still no lower than the leaf spring pivots or the Westin step bar.

All connectors connected. The black hose is the compressor air intake, which is routed along the drivers side frame rail and under the hood, where it connects to the filter.

My work will never be mistaken for that of a professional. Note the missing bolt in the flat piece of 3/16" steel - sometimes you just get sick of drilling 4 bolt holes when 3 will do just fine.

Overall, I could not have been more pleased with how the tank and compressor fit within this space. Unless someone sticks their head under the Blazer, they'll never know what's there. Combined with the stealthiness of the horn mounts, this is a relatively uninspiring add-on for those interested in taking your ride. And best of all, nobody will ever expect 150 or so decibels coming from this vehicle.