Yet another A/C to air compressor conversion ('99)

Finished this tonight! :yelclap:

'99 XJ, the A/C barely worked, and whenever it was hot enough to really want it, it would overheat the engine without much effect. Since I'm putting an ARB locker in my new d44 front axle, I needed a compressor and I've been wanting on board air for a while anyway.

So here's what I ended up with. It's slightly more complex than some of the builds I've seen, but I wanted something that will work well and leave room for expansion.

Tested it out, it takes 2 minutes to fill my tank at idle, 51 seconds at about 2000 rpm

If anyone wants details I can provide an exact list of everything I used.

Intake assembly. Stainless mesh filter, air tool oiler.


Output assembly. Filter, check valve, 3-port manifold, 110/145 pressure switch, line to the interior, 150 psi relief valve (well, currently a plug I'm still waiting for the valve to arrive in the mail).




Interior Manifold. From bottom to top, the line to the tank in the trunk, the line to the compressor, line to the dashboard gauge, regulator, and switch for the locker


Dashboard pressure gauge. The switch for the compressor is the far right of the lower row, just past the ignition switches. It was my A/C switch, I just cut out the old pressure switches and wired in the new one. To make up for the thickness of the metal, I wrapped a piece of 14 gauge wire around the inside of the cover to keep the glass from moving. And I still need to cut off a 1/4" of plastic behind the gauge so I can tighten down the dash piece, that's why there's a gap under the vent controls.






I still have to mount the tank, hopefully before the weekend. I plan on mounting in upright next to the second battery and inverter. It's a 4 port tank, with a T on the input end. There's 3 output ports, a gauge, and the input. The input has a cutoff valve so I can disconnect it without draining the tank.

Damn thats a 99? Ive seen 89's with cleaner engine bays! Nice install though, that dash looks neat

Midwest mud and 200k miles will do that. And thanks, I built that dash about 2 years ago, it's proved very useful for mounting switches.

I did the same conversion in my '88.

I love it. MUCH faster than any electric I have seen so far.

Im sure you havent been running this setup long enough to know yet, but maybe someone else does. How often do you need to fill up the oiler? I was thinking about running the larger sized oilers for compressors, rather than the airtool size, but if its not neccessary then ill go with the same deal the OP did. :gee:

Check it every couple trips. The oiler I used doesnt have a window, so I have burned up two compressors so far.

The top end never goes, its always the sump for the wobble plate that goes dry. When I get home for thanksgiving I will try to locate another one, and plan to do a write up with a couple Ideas i have stuck to the cobwebs in my head.

I had heard of too many people burning out their A/C units with those little oilers so I went for one of the larger ones that looks like your filter. It is nice because it has a big glass reservior that you can easily see the oil level in. I topped it off with compressor oil and have filled all my tires up from 8-32 psi at least a dozen times along with several friends tires and my oiler is still about 1/2 full.

I squirt some compressor oil in mine every once in a while, as well as keeping the inline oiler full. I run a small ARB compressor just for my locker. I use the AC air for tires and impacts mostly. So I oil it before use just like you would any airtool.

austinaubinoe said:

I squirt some compressor oil in mine every once in a while, as well as keeping the inline oiler full.

Click to expand...

I think I may do that.

I got a friend coming out to Vegas for the week so we're taking both my Jeeps out on some light trails Saturday, so I'll get to try out the compressor airing up 8 tires afterward, see how well it works.

Interesting, I like it! I actually have most of the parts for this sitting in my bin waiting to be installed in the 96.

Just a heads up... make sure you install kill valves on all the non-essential air lines, that way if you break one off somewhere, you can close it off and still have air for your air lockers.

Mounted the tank tonight, I just welded a piece of angle to the wheelwell, the tank is held on plenty tight by the two rubber bungies, but that way I can disconnect it real easy. So other than tightening a couple slowly leaking fittings, I guess it's done for now

89heap said:

Im sure you havent been running this setup long enough to know yet, but maybe someone else does. How often do you need to fill up the oiler? I was thinking about running the larger sized oilers for compressors, rather than the airtool size, but if its not neccessary then ill go with the same deal the OP did. :gee:

Click to expand...

There is a way to take the guess work out of oiling Sanden compressors. I've been running OBA off of my Sanden for 6 years and have burned up at least half a dozen compressors.

Last year I replumbed it connecting the drain from the coalescing filter though a check valve to a fitting on the side of the compressor. Now I have a closed oiling loop and haven't had a problem since, also changed to Mobil 1, 0-5w synthetic oil. I put about 4 ounces of oil in the compressor and haven't worried about it since. This year sometime I plan on flushing out the oil and putting in fresh oil. My air tank is below the radiator so it is the lowest point in the system and is easy to reach, since I drain the water regularly.

The way it works is the coalescing filter separates oil from the air and will automatically dump the oil that has collected once it senses there is about an ounce in the resovior. The oil from the filter enters the line under system pressure and stays there until the compressor is not running, once the compressor stops running the pressure in the compressor drops allowing the oil in the line from the filter to enter the compressor. The check valve keeps the pressure from the compressor from pushing the oil backwards to the filter.

I will try and post some pics on here today.

Jerry H

Here's what my setup looks like.

http://i1087.photobucket.com/albums/j463/JerryRH/MY%20XJ/DSCF0963-1.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0969.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0968.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0967.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0965-1.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0964.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0963.jpg
http://i1087.photobucket.com/albums/j463/JerryRH/MY XJ/DSCF0962-1.jpg

Since my OBA also runs the ORO AiRock and SwayLok you can see that I have alot more plumbing involved. Once I find a job I'll be adding train horns and a two gallon tank for them. I'm tired of these lousy Minnesota drivers changing lanes without looking and not hearing my horn.

I've got a fire truck horn for the same reason... saw it in the junkyard one day and said "I HAVE to have that!"

SC Rednek said:

Mounted the tank tonight, I just welded a piece of angle to the wheelwell, the tank is held on plenty tight by the two rubber bungies, but that way I can disconnect it real easy. So other than tightening a couple slowly leaking fittings, I guess it's done for now

Click to expand...

I'm in the process of getting the parts for mine, where did you get that tank, it's the one part I'm having trouble finding.

tbones88XJ said:

I'm in the process of getting the parts for mine, where did you get that tank, it's the one part I'm having trouble finding.

Click to expand...

I've got two of those sitting in my garage, looking for a new home. I ran that until I decided I didn't need that big a tank and switched to a one gallon tank.

Jerry H

I bought my tank from someone here on I think a little over a year ago. If I remember right it was originally built as an air ride tank. Rated to 150 psi.

Filled up all 8 tires yesterday before driving back. Everything ran great, but the lines got pretty hot after filling 6 tires so I let it cool down for 10 minutes before finishing. I'm not happy at all with the oiler, after the first four tires and the couple tank fills I ran testing it last week, the oil level hadn't gone down at all. So I took off the filter and started dripping some compressor oil straight into it.

So what brand oiler should I use? I'm ok without an oil feedback loop, oil's cheap. I just haven't seen anything for sale locally.

Jerry_h said:

There is a way to take the guess work out of oiling Sanden compressors. I've been running OBA off of my Sanden for 6 years and have burned up at least half a dozen compressors.

Last year I replumbed it connecting the drain from the coalescing filter though a check valve to a fitting on the side of the compressor. Now I have a closed oiling loop and haven't had a problem since, also changed to Mobil 1, 0-5w synthetic oil. I put about 4 ounces of oil in the compressor and haven't worried about it since. This year sometime I plan on flushing out the oil and putting in fresh oil. My air tank is below the radiator so it is the lowest point in the system and is easy to reach, since I drain the water regularly.

The way it works is the coalescing filter separates oil from the air and will automatically dump the oil that has collected once it senses there is about an ounce in the resovior. The oil from the filter enters the line under system pressure and stays there until the compressor is not running, once the compressor stops running the pressure in the compressor drops allowing the oil in the line from the filter to enter the compressor. The check valve keeps the pressure from the compressor from pushing the oil backwards to the filter.

I will try and post some pics on here today.

Jerry H

Click to expand...

Yes, the compressor does get hot, that is why I have a 6' braided stainelss line coming off the compressor to help cool it down before it gets to any other components that might have plastic or be heat sesitive...

Did you adjust the flow on the oiler when you installed it? There should be an adjusting screw on it somewhere.

I used a cooling coil to keep from melting the rubber parts of the system. Just take 5 or 10 feet of 3/8" copper tubing and wind it around a spray paint can, add your ends, and Viola! no more melty hoses!

Jerry_h said:

Yes, the compressor does get hot, that is why I have a 6' braided stainelss line coming off the compressor to help cool it down before it gets to any other components that might have plastic or be heat sesitive...

Did you adjust the flow on the oiler when you installed it? There should be an adjusting screw on it somewhere.

Click to expand...

I didn't see any screws other than the fill hole screw, I'll take a good long look at it tonight and see if I missed anything.

How'd you attach the copper or stainless tube to the aluminum output tube without at least a short section of rubber in the crimped on end?