ExtremeAire OBA

By Jeep Experts

My buddy Mike had been Jeepin’ for just a few years and determined he wanted one thing extra substantial than his ARB compressor for airing up his tires.  He had used it for numerous years on his 33″ tires and now that he had switched to 35″ rubber, the low airflow was r-e-a-l-l-y displaying its quick comings.  Mike had wheeled sufficient with me to know the restrictions of my QuickAir2, which can also be a low airflow compressor however not as dangerous because the ARB unit.  I truthfully don’t know if he had thought of a CO2 system however I do know he was in no hurry to cram extra stuff below his TJ’s hood (no need to do a York OBA).  That narrowed his selections right down to an electrical compressor however with cheap sufficient airflow to fill the 35″ tires with out taking all day. 

Enter the ExtremeAire extreme obligation compressor from Extreme Outback Products.  In quick, the ExtremeAire makes use of a 12 volt 3/4 horsepower fan cooled motor to offer steady obligation (100%) airflow.  With a max working strain of 150 PSI and a 4 CFM free circulate charge, the compressor does a reasonably good job filling up tires on the finish of the path.  Another native Jeeper I share trails with has been utilizing one for a few years now and I’ve watched it fill his 35″ tires fairly successfully.  The compressor additionally has a washable air cleaner on it to assist preserve the mud the place it belongs (outdoors of the compressor). 

Mike stopped by my home on a Saturday to kick round some concepts of the place to mount the compressor and the 1 gallon air tank he received on the 4AJUMR door prize raffle.  I had some aluminum strap within the storage and after exploring just a few concepts, we determined that one thing much like the above mockup might be made with hand instruments and bolted into the rear of the TJ.  We took some measurements and wrote down the lengths and amount wanted to make Mike’s OBA mounting rack.

Mike was off work on July 4 and after he referred to as me about mid-morning, I headed over to his place to assist with the rack building.  While I drove throughout city to his place, he made a rapid journey to a close-by metallic retailer and picked up the 1.5″ vast x 3/16″ thick metal strap we’d be utilizing.  The proprietor was form sufficient to pre-cut the items for Mike.  As it was, we ended up doing just a little trimming on some items as we acquired into the venture however higher to be too lengthy than too quick.  So armed with some c-clamps, a bag of 5/16″ fasteners contemporary from the ACE ironmongery store, and the minimize metallic, we began constructing the mounting rack.

The first step was to tough out the placement and spacing for the rack.  A chunk of two×4 held up one finish whereas we checked for correct clearance on the compressor and tank.  Although Mike is working a tough prime now, he needed to make sure he might correctly fold a gentle prime down alongside the facet of the rack with out hitting the compressor or air tank.  This was a kind of initiatives the place you needed to measure twice and solely minimize as soon as. 

After trimming a few the rack items to the right size, Mike fired up the outdated drill press and put just a few holes at what we hoped can be the right areas.  As it turned out, our measurements have been proper on the cash and no holes needed to be slotted or elongated to ensure that every thing to bolt collectively.

With the requisite holes drilled within the items, we staged the compressor and air tank on the ground with some bolts within the holes to verify we hadn’t missed something.  A fast {hardware} depend revealed we had truly gotten sufficient of every thing wanted apart from one bolt.  We hadn’t counted on the additional size wanted for one in all them that went by some further brackets that have been utilized by Mike’s outdated tire service.  No drawback, what we had would work for the take a look at match and he might choose up the remaining throughout the subsequent journey to the ironmongery store.

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Here is the primary take a look at match.  It all went simply the place we needed it to go.  We drilled a half dozen holes into the fender properly space to complete up the mounting factors.  The last item to do was the bracket to assist the top of the rack.  You can see it hooked up to the bolt on the air tank.  At this time, Mike just isn’t positive if he’ll want one other bracket to assist the rack below the compressor.  The bracket was shaped by spending a couple of minutes with the vise and a really massive hammer (yeah, not probably the most elegant method nevertheless it did the trick and turned out good).  Edit:  Since Mike had the fabric readily available, he bent one other bracket, much like the primary one, and situated it below the compressor.

Mike didn’t need assistance with the disassembly and portray.  He will try this throughout the evenings when he will get a little bit of spare time.  As with most of us, we work on the Jeep when time permits (until it’s your day by day driver and also you HAVE to get it mounted so you may get to work tomorrow).  After it’s painted and put in, we are going to begin plumbing the compressor to the tank and as much as the air manifold (which now we have but to make).  Mike will choose up the suitable sized electrical wire to offer energy to the compressor in addition to an influence relay and fuse/circuit breaker.

ExtremeAire OBA

A few weeks had passed by since Mike and I labored on his OBA setup.  During that point, he painted the rack and ordered just a few venture elements from an on-line  retailer.  When they arrived, I headed over to his place to see if we might make some extra progress.

Mike determined to make use of a Maxi fuse for the primary energy feed to the ExtremeAire compressor.  The holder was obtained and a 60 amp fuse was discovered on the native ACE ironmongery store (it by no means ceases to amaze me as to the number of “stuff” that retailer carries).  We put terminal lugs on the 8 gauge pigtails and made it prepared for set up between the optimistic terminal of the battery and the management solenoid.

You can see a portion of the management solenoid within the above image.  8 gauge audio amp energy cable linked the output terminal of the management solenoid to the optimistic energy lead of the compressor.  A butt splice was used to attach the leads on the compressor.  The destructive lead of the compressor motor was linked to one of many close by mounting fasteners utilizing a crimp on ring terminal.  The chassis floor for the destructive lead labored simply fantastic, as we later confirmed.  The management solenoid was mounted on the passenger entrance fender properly, about 6 inches from the battery.  This location allowed the Maxi fuse holder for use with out the necessity of splicing an extension to the holder’s leads.



Mike had a spare ARB strain swap which he pressed into service when he realized that the one he had ordered had but to reach.  A “T” was put in one of many 1/4″ NPT bungs on the tank and to it was linked the ARB strain swap and a 150 PSI pop-off security valve.  The security valve will routinely open and launch tank strain ought to the strain swap malfunction and never flip off the management solenoid when the 105 PSI higher regulator restrict is reached.  Before wrapping it up, we put some warmth shrink tubing on the strain swap’s electrical connectors.  You wouldn’t need these +12V terminals uncovered though the solenoid management circuit is protected with its personal 15 amp fuse.  The the rest of the management solenoid circuit is a splash mounted energy swap.  When the sprint swap is turned on, tank strain is managed utterly by the strain swap.  When turned off, the solenoid is not going to energize and the compressor is not going to preserve tank strain.

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3/8″ gentle copper line was used to attach the compressor to the tank.  It was determined to place just a few coils within the line to assist dissipate the warmth that’s generated by compressing the air.  I believed it was an ideal thought since it’s in regards to the prefect measurement to warmth a can of soup.  (I’m wondering what number of tires need to be stuffed earlier than the soup is prepared?)  We discovered that the hearth extinguisher made a superb type on which to bend the copper line.  90 diploma compression becoming have been used on the copper line on the output of the compressor and the inlet of the 1 gallon tank. 

Just in case anybody is questioning, the mounting rack as designed is greater than sturdy sufficient to carry the compressor and tank in place.  We used massive fender washers contained in the wheel properly the place the 5/16″ fasteners safe the rack.  Nyloc nuts have been used to assist guarantee issues didn’t vibrate aside.  Once we had tightened the mounting bolts, we discovered that we might rock the vehicl facet to facet by pulling on the rack.  Yep, it was not going anyplace.  A good friend of mine was involved that the three/16″ strap wouldn’t be as much as the duty.  I imagine he’ll change his thoughts as soon as he sees it first hand.  (You can see the second bracket that Mike added, below the compressor.)

Once the air line fast disconnect is screwed into the tank, this a part of the venture will probably be executed.  I requested a good friend of mine to bore a gap by the center of some 1″  aluminum spherical inventory.  The plan is to make use of a 6″ lengthy piece, drilled and tapped for the suitable fittings, as an air manifold for the ARB compressor solenoids.  This will permit Mike to make use of the ARB compressor or the ExtremeAire as a strain supply for his ARB lockers.  Switching between the 2 will probably be as straightforward as transferring the short disconnect from one compressor to the opposite.

When we get that half completed, I’ll snap just a few pics and embrace them on this write-up so I can name this executed.

ExtremeAire OBA

Another Saturday rolled round and Mike and I acquired collectively to complete up his OBA venture. 

Here is an up to date image of the compressor and tank.  Mike put in a fast disconnect air coupler for the hose he makes use of to fill his tires.  You also can see the black 3/8″ hose hooked up to the top of the tank.  It exits the inside of the TJ by way of an present rubber plug (now with a .65″ gap in it) within the flooring of the bathtub and runs to the engine compartment,  taking the identical route because the fuel and brake traces do alongside the facet of the body. 

While the main objective of this new OBA setup was to offer Mike with a superb air up supply for his 35″ tires, he additionally needed it to operate as a backup to his ARB compressor for working his air lockers.  This meant he wanted a simple method to swap between air sources, a plug and play sort of answer, whereas on the path.  While Mike has not had any issues along with his ARB compressor, we each agreed that passing up the chance for a backup air provide was simply asking for Mr. Murphy to pay a go to on the path some day.  With that in thoughts, we labored out a ten second answer to change between each air sources.

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Both Mike and I had some air manifolds drilled for this venture.  I had a pair constituted of 1″ aluminum spherical inventory and Mike had a pair constituted of rectangular inventory.  When we acquired collectively, we exchanged manifolds and Mike determined to make use of the one he introduced because it was simpler to mount.  Unfortunately, it had been tapped for 3/8″ NPT fittings at every finish which he hadn’t counted on.  (He assumed it was going to be tapped for 1/4″.)  No biggie….a spare 3/8″ hose barb was put into use and it labored simply fantastic.


The 25′ size of three/8″ Goodyear air hose that Mike had was greater than lengthy sufficient to succeed in from the air tank (at the back of the TJ) to the engine compartment.  He minimize off a 2′ size and hooked up a fast disconnect air coupler (the identical sort that the ARB compressor could be fitted with).  A 3/8″ hose barb was screwed into the air manifold and the two′ hose was hooked up to it.  The air manifold had been constructed with 4 holes drilled by it to facilitate mounting.  The air ports included a pair of three/8″ NPTs that have been situated at every finish, a pair of 1/8″ NPTs, and a single 1/4″ NPT port. 


A plug was inserted into the 1/4″ port (it was meant to be a spare).  The ARB solenoids have been faraway from the ARB compressor and put in of their new areas, both facet of the unused 1/4″ port..

It must be famous right here that the ARB solenoids do NOT use a typical 1/8″ NPT becoming however quite a 1/8″ BSPT becoming.  The main distinction between the 2 is that one has a thread depend of 27 TPI whereas the opposite is 28 TPI.  Depending on who you speak to, some say you possibly can put an everyday 1/8″ NPT into the BSPT tapped gap and there received’t be any issues whereas others say it would leak.  Mike opted to do it the conservative means and bought a few 1/8″ NPT to 1/8″ BSPT fittings (male to male coupler) from McMaster-Carr’s on-line catalog, simply to be secure. 

The 3/8″ Goodyear hose was secured within the engine compartment with some cable ties and a feminine air coupler was hooked up to the top of the hose.  Mike plugged the holes within the ARB compressor with the 1/8″ BSPT (you probably did preserve those that got here within the compressor, proper?) plugs.  Since his ARB compressor has the non-compulsory tire fill air coupling on it, the hose on the brand new air manifold will probably be snapped into this air coupler for regular operation.  If an issue ought to come up with the ARB compressor, he can merely disco the two′ hose from the ARB compressor and snap it into the Goodyear hose air coupler.  The ExtremeAire compressor and tank will then provide the ARB air lockers with air.  It was because of this that Mike used an ARB strain swap to manage the ExtremeAire compressor.  The air lockers won’t ever know the distinction. 

Once again dwelling, Mike did a fast leak take a look at on the system utilizing the ExtremeAire because the supply.  He stuffed the tank and cycled the air lockers about 10 instances.  He then turned the ability swap off and waited 20 minutes earlier than turning it again on.  The compressor didn’t begin up which implies the tank had NOT leaked down sufficient for the strain swap to activate the compressor.  He had despatched me an e-mail with this information and stated he was going to examine it in an hour or two and to if it the compressor would begin.

Well, that’s about it.  Like Mike stated, this venture is DONE!   I hope this has given you some perception in to yet one more means by which you’ll be able to set up your individual OBA system from items and elements.  Good trails and bear in mind to TREAD Lightly! 


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