My Onboard Air Compressor

There is nothing better on the trail than On Board Air.  You can use it to fill your tires at the end of the day.  You can use it to run air tools, and if you have ARB's, you can use it to control your lockers. I installed an onboard air compressor using the Kilby Installation kit for my TJ from www.onboardair.com.  It worked really well.  The quality of the parts was excellent, and everything matched up exactly as it should have.  The actual installation was really easy.  Here's how I did it.

I already had a York compressor laying around, so I didn't have to hunt for the compressor.  I did need a new bracket and serpentine pully, though, hence the Kilby kit. 

Before I started the installation, I sat down and figured out what I needed:

1.  I needed an oil filter.
2.  I needed a pressure gage
3.  I needed a pressure switch (most important item)
4.  I wanted a tank

Here's what I came up with:

This is the same basic setup I've seen on a bunch of other sites, but this is the way to do it. I have a 2.5 gallon tank from summit racing.  You can see it in this picture:

That's the flowmaster on the left.  The tank is on the right. It sits inside the frame rail, and I haven't hit it yet. Here's what it looked like on my CJ7.  I have the same basic setup on my TJ.  Some of the fittings are different, but otherwise it's the same.

Here's a list of the items I used for the conversion:

1.  3/8" barbed connectors with 3/8" male fittings (used one on output hose from compressor and one on output hose from tank, with hose clamps)
2.  3/8" male/male nipple fittings (used 2, between oil filter and regulator and between regulator and pressure switch)
3.  3/8" T-fittings (used 1 for the pressure switch)
4.  3/8" female quick disconnect, attached to output hose from tank
5.  3/8" female connectors for quick disconnect (male fitting for quick disconnect, female threads for pipe fitting)
6.  50' coiled air hose
7.  50' rubber air hose (to make smaller hoses with)
8.  Air Chucks
9.  Air Gun
10. Teflon Tape 

When I got my compressor from the junkyard, I made sure to cut the hoses coming from the compressor with their original fittings.  I took them and fitted the barbed connector into the discharge hose.  I then connected the oil filter to the connector on the hose.  Using a male/male nipple fitting, I connected the output of the filter to the inlet of the regulator. Using another male/male fitting, I connected the T-fitting to the output of the regulator.  The pressure switch was connected to the "T", and the other end was connected to the input hose for the tank (in this case, the existing AC condenser). I then fitted another barbed connector to the output hose from the tank, and then fitted the female threaded quick disconnect couple to that, and presto!  I have an air system!  I set the pressure switch to turn the compressor off at 115 PSI, and it comes back on at 60 PSI.  I would have liked this differential to be a little smaller, but the switch wouldn't let me do it.

On the inlet side, I went to AutoZone and found a nice little Breather Cap filter for around $12.  I cut out the rubber fitting and pressed it onto the inlet connector on the compressor.  It looks really trick, and will keep evil-nasties out of my compressor.

And that's all it takes!  Of course, if you don't already have the compressor installed in your rig, this will be a little more complicated.  When you go to the junkyard to get your compressor, make sure you get ALL of the mounting brackets that came with it, if possible.  Also, try to find one on an AMC for a better fit.

Good luck!