On Board Air

QuickAIR 2

One of the first true upgrades I installed on my CJ was its on-board air compressor. What really started the thought was that I wanted to be able to try airing down my tires, but I didn’t want to have to drive that far on the pavement to bring the tires back up to their highway pressure. I also thought it would be nice to have compressed air for other conveniences like inflating camping and fishing gear, or blowing the dust out of parts and places while enjoying the off road.

I looked around and did some research and chose the QuickAIR 2 compressor. Partly due to its reputation, and party due to its two-position mounting option. I debated about whether I wanted the portable version or the hard mount version. After a couple of seconds, recalling just how much space there really is in a CJ when you try to pack it for a camping trip, I felt the hard mount option would be more convenient – and it would be there when I needed it.

Deciding on the compressor was the easy part. Then, before ordering it, I discovered (via the Internet) that there were several additional options that could go along with the air compressor. Sun Performance Products makes a 2.5 gallon air tank that is nicely shaped. They also make a mounting kit that includes a pressure switch, a relay, a bunch of hose, an air chuck, and a pressure gauge to mount in the cab. So I ordered the whole works!

When everything arrived I discovered the air tank was a little larger than I anticipated. Originally, I intended to mount the tank under the hood on the fender well – just below where I planned to mount the compressor. Where was it going to fit? I carried it around the CJ top and bottom looking for a safe place to mount it. I finally settled on a spot below the passenger seat, along side the frame rail.

Air tank "as is" without cosmetic hype!   Air tank mounting location - fuzzy (sorry)

I first put the compressor on the fender well, where I originally intended. I think it would have fit upright, but I decided to lay the top part over 90 degrees to be safe. The base of the compressor mounts on rubber grommets to buffer the vibrations from loosening the mounting hardware.

QuickAIR 2 mounted on fender well

I then went through the instructions for the mounting kit, which had you remove the on/off switch from the compressor, and patch in the relay and circuit breaker. Then I wired the power source to the compressor, which runs through the relay and into the cab where you install the on/off switch taken from the compressor.

Back at the air tank, there are several threaded ΒΌ inch holes that provide a number of options for mounting. Since the tank was going to "hang" from the CJ, I installed the drain valve on the top of the tank (bottom), and the pressure switch on the side. The main air inlet and outflow are mounted on the ends of the tank. The holes I haven’t used (yet) are fitted with plugs.  (Someday, I plan to use this tank for the ARB lockers, and will take advantage of the remaining holes.)  After all the fittings were installed on the tank, I mounted the tank to the floor of the CJ, and used the frame rail and skid plate to protect the tank from incidental abuse.

Once the tank was in place, I installed the pressure gauge inside the cab and connected the small hose line between the gauge and the tank. Next was the main hose between the compressor and the tank. Finally, the last part was to find the location for the quick disconnect air chuck.

Air gauge mounted on dash.

I settled on a location near the back of the CJ. Shortly behind the back of the tank, I noticed a hole on the inside of the frame rail. I noticed there were several holes on the outside of the frame rail behind the rear axle. So I routed the hose through the holes, down the inside of the frame rail, to the back end. I bought a brass 90-degree elbow with one male and one female end. I mounted the hose connector to the female end and (using the long slotted hole on the frame) fed the male end of the elbow out the smaller hole. Once the threads were through the frame, I installed a rubber washer and then the quick disconnect air chuck.

Air chuck at the back end of the frame

The last part I needed was an air hose for reaching the tires from the air chuck. I discovered the yellow 15’ coiled air hose works perfectly. It reaches all the tires, then (sort of) recoils and stays beneath the rear seat when not in use. I also installed another quick disconnect air chuck on the end of the hose and carry an assortment of fittings for use with the compressed air.

Unfortunately, the output is not enough to run very many air tools. But it makes quick time in refilling my 31" tires.  I find it takes about 2 1/2 to 3 minutes to bring my tire up from 10 pounds to 26 pounds.  This includes the time it takes to stop and check the air pressure a few times! 

With the pressure switch, the compressor comes on automatically when the air tank’s pressure drops below 85 pounds and shuts off automatically when the tank pressure reaches about 105 pounds.


After having the compressor for almost two years, I still believe this was a very valuable addition to the Jeep.  If I was starting all over, this would still be one of the first upgrades I'd make to the Jeep - but that's just me.  I use it for something almost every time I go off-road.

The only problem I have had with this particular set up has been associated with the location of the air chuck.  While the original intention for this location (see above photo) was to be inconspicuous, the air chuck gets rather dirty from the mud and grime from the rear tire.  This had caused some difficulty in getting the male end of the connector to stay locked onto the chuck.  I have found a suitable solution to the problem to help in this dilemma - to see it!