The addition of the ARB lockers to the front and rear axle resulted in my installing an ARB air compressor. To date (about 3 years as I write this), I have had zero problems with the ARB compressor and the air lines used to actuate the ARB lockers. However, I've always been one to stack the deck in my favor (when I can) when it comes to trail reliability. So, after helping MikeW with his ExtremeAire OBA installation, I decided I might was well upgrade my QuickAir2 setup so it could be used as an alternate ARB air source should the need arise. The expensive parts for such a backup (the compressor) was already in the Jeep. All I needed was some odds and ends to make it into a backup air source for the lockers. I didn't want the project ballooning into an black hole where I could pour more money....I wanted to do this on a shoe string budget but still keep things safe and reliable.
No, that is NOT an old 5# CO2 fire extinguisher.....it is an OBA tank, just waiting to be modified and put into use. The QuickAir2 has a very small air chamber on it and, in my opinion, it really does not lend itself to be setup with air solenoids and a pressure switch like the ARB compressor uses. I just couldn't see myself attempting to make the QuickAir2 into a clone of the ARB. So, I decided that I would add a small air tank and mount a couple of the necessary components on it.
After the tank was disassembled, I drilled 3 holes in it (one on the bottom, two on the top) and got Troy, of Toys by Troy, to weld in some 1/4" NPT bungs. I bent some 2" wide strap into a couple of mounting brackets and had the brackets welded to the tank. After a session with the wire brush, a few coats of satin black rattle can paint got the tired old fire extinguisher looking pretty good.
I stopped by MikeW's place and we drilled some holes in the passenger side fender. A handful of 5/16" bolts, Nyloc nuts, and some fender washers put the tank securely in place. Mike even had some under coating left over so he gave the mounting hardware a coat of it so it would blend in with the rest of the inner fender. (The plastic liners went away some time back about the time that the LED lights were installed.) I used 1/4" soft copper tubing to connect the QuickAir2 to the newly installed air tank. 1/4" compression fittings were used at each end of the tubing. A threaded reducer was used to on the extinguisher's neck opening to size it for the 1/4" tubing fitting. All of the fittings and tubing were obtained at the local ACE hardware store. Nothing fancy here....just plain old brass hardware fittings. The tank was fitted with a couple of 1/4" 90 degree fittings to which a quick release air fitting and an ARB pressure switch was installed. Since I wanted this setup to properly actuate the ARB lockers, should the need arise, I opted to use my spare ARB pressure switch to keep the tank pressure within ARB limits. I was a little apprehensive about the QuickAir2 being able to generate enough pressure to actuate the pressure switch since both are rated at 105 PSI. As it was, the compressor was able to generate adequate pressure to turn itself off. I used a 40 amp relay to control the main power to the compressor. The ARB pressure switch is connected into the relay's control line, along with a dash board power switch, to regulate tank pressure and control power to the compressor, respectively.
My ARB compressor is mounted in the engine compartment. The ARB air lines originate from the compressor's air solenoids. In order to easily make the QuickAir2's air tank a source for ARB air, it was necessary to remote the air solenoids (and thus the blue air lines) from the ARB compressor. This is done using an air manifold. An air line from the QuickAir2's tank is routed to the engine compartment to provide the backup air for the lockers.
I got a friend of mine to make a couple of air manifolds from some aluminum round stock. The hole running the length of the aluminum was the size needed to tap the piece for a 1/4" NPT fitting. After the center was bored to the correct size, I tapped it for 1/4" NPT and then drilled a couple of ARB solenoid mounting holes and tapped them for 1/8" NPT.
It should be noted here that the ARB solenoids do NOT use a common 1/8" NPT fitting but rather a 1/8" BSPT fitting. The major difference between the two is that one has a thread count of 27 TPI while the other is 28 TPI. Depending on who you talk to, some say you can put a regular 1/8" NPT into the BSPT tapped hole and there won't be any problems while others say it will leak. When MikeW was making his manifold, he opted to do it the conservative way and purchased a couple of 1/8" NPT to 1/8" BSPT fittings (male to male coupler) from McMaster-Carr's on-line catalog, just to be safe. I had him pick me up a couple at the same time and used them on my manifold. The ARB solenoids that were in the ARB compressor were removed and used in this manifold. I used a conduit clamp (for holding conduit in place) on the manifold to secure it in the engine compartment.
I had a 25' length of 3/8" air hose, rated at 225 PSI working pressure, that I bought at a surplus sale. It was new and already had the necessary quick disconnect fittings on it. I cut 2' of the end of the hose that had the male fitting on it. Using the 3/8" hose barb that was screwed into one end of the manifold, I attached the 2' length of hose to it.
Meanwhile, back at the original ARB compressor, the solenoids were removed, cleaned, and reinstalled on the air manifold (the one with the 2' length of hose attached to it). The pressure switch was removed from the compressor and a 1/4" NPT t-fitting was screwed into its place. The pressure switch was attached to the new t-fitting along with a female air hose quick disconnect. The holes in the compressor where the air solenoids were located were plugged with the same plugs that came with the compressor. (I knew I kept those shiny little plugs for a reason).
Although not easy to see, the air manifold is shown in position, mounted at the edge of the tray that the ARB compressor is bolted to (with the 2 blue air lines going to it). The factory ARB wiring harness was sufficient to accommodate the relocation of the air solenoids on the newly installed manifold. You can see the red rubber hose going from the manifold to the ARB compressor. If needed, this same hose can be easily disconnected from the ARB compressor and attached to the air line that runs from the QuickAir2's tank at the rear of the vehicle. The backup ARB air source is now fully functional and can be enabled in about the same amount of time it takes you to lift the hood on the TJ.
That is about it for this modification. It's pretty simple to do and was easy enough on the budget too.
Good trails and TREADLightly!
4x4 Off-Road Homestead Firearms RC Flying