ARB Compressor Mount for TJ

I run it and have had good luck but also have mixed feelings about it.  It does put the compressor in an easy spot that doesn't conflict with under hood space but it is about the hottest place in the engine compartment.  Also it shipped with the wrong length metric bolts so i had to source new ones prior to mounting.

I have seen 1 photo of someone successfully mounting one under the booster on the un-used ABS tray but that wouldnt work for mine being a manual and having the clutch master cylinder in that area. (i cant seem to find that picture again but it is out there)

The company grabarusa sells one for mounting inside behind the driver seat that could work with a little modification so long as you dont use the back seat area for people. https://grabarsusa.com/arb-compressor-twin-air-CKMTA12-bracket

I like the idea of putting the compressor inside as it is away from dust and engine heat but dont like the idea of running large power cables through the firewall.

The other option that I was considering was ditching the cruise control or moving the actuator to the ABS tray and/or running a small washer fluid bottle and then placing the compressor on the drivers fender in that location.  (as in this picture: https://www.wranglerforum.com/f282/air-arb-v-vair-144124.html#post2107911)

Thanks for the information Kris. I currently have a smaller ARB compressor for my lockers mounted under the hood on the drivers side inner fender. I also have a Viair compressor for airing up mounted on the driver's axillary batter tray. So if I get the twin compressor should I eliminate my other compressors and use the twin for lockers and airing up or keep my small ARB just for the lockers?

Up to you.  There are actually 3 sizes of ARB compressor: the mini for just lockers, the small for tires, and the large twin (which is two of the smaller ones mounted together).  If you already have the larger of the single compressors you could just swap the viair for another one of those have still have the same flow as the twin with less cost.  The Viairs are slower than the larger single ARB but will go up to 200psi so if you added a tank you could start the viair filling the tank 5 minutes before reaching the parking lot to speed up air times without replacing the compressor.

That said, the twin compressor harness already had terminals and plugs for the switches so it would be a very simple installation for you.

I haven't had that particular bracket. But I have had other M.O.R.E products/brackets and they have been solid-beef and top notch quality.

kris_olof said That said, the twin compressor harness already had terminals and plugs for the switches so it would be a very simple installation for you.  

I believe I have the ARB mini that just operates lockers. So if I go with the ARB Twin CKMTA12 I’m not sure how to set it up. Right now I have an ARB compressor switch and a front and rear locker switch mounted in the dash. There is only room for three switches in this location. So if I used the ARB Twin CKMTA12 to operate my lockers and to inflate my tires how should I set it up? Can I use the existing switches or do I need to do something different? I suppose I would need to install the new compressor wiring harness at a minimum.

In looking at the ARB twin installation instructions (https://www.4wd.com/sku/ARB%204x4%20Accessories/standard/CKMTA12.pdf) it says that you need to install an air locker manifold (ARB part #17503 link). I believe I could use my existing solenoids and hoses and just mount the locker manifold where my existing ARB compressor is now (see photo below). I think I would just need a longer braided hose to go from the compressor to the manifold.

In looking at the photo in the installation instructions it looks like the manifold has a quick release installed in one of the outlets. I assume this is where I would attach the braided hose that I currently have on my Viair to air up tires. Am I correct to assume that the twin operates in the same pressure range as my mini or that it operates in a range that is fine with my existing lockers and hoses?

If I do go with the twin then does it make sense to add an air tank? If so, how does this change the set up and where is a good place to mount it?

I have spent many hours researching this exact series of questions before I bit the bullet and went with the ARB twin.  Luckily I saved some of the research and instal photos.

My favorite part of the ARB compressor setup is the premade harness, only need to crimp on the proper ring terminals for the 2 positive and 2 negative leads.  The harness that comes with the twin compressor is pre terminated with connectors and has a switch feed for feeding through the firewall to the interior switches.  Depending on what connectors your old ARB stuff has you will be looking at worst splicing the solenoids and crimping new connectors to connect to you switches.  At best you will be re-using the switch harness inside and just connecting to the new underhood harness that comes with the compressor.  Inside you will see no change as the existing "compressor on" switch will trigger the compressor to cycle at its proper pressure for the lockers/airing up and the locker switches will continue to operate the solenoids.  Here are some pictures from my install of the harness.

You are spot on with the manifold and braided cable questions.  I am thinking there might be enough room to squeeze the twin compressor in approximately where your current ARB mini is located as the compressor itself is pretty flat and with a braided line coming off it you wouldnt need much clearance between the hood and compressor.  I cant find any pictures of people doing that anymore but there is this pic from TNTcustoms that fit the compressor on top of their tube fenders.

As for the air tank, I purchased one and will be adding it to the LJ.  All you need to do is plumb it in-line with the rest of the air system if you are ok with waiting for the tank to reach pressure before your lockers engage.  If you want the lockers to work more quickly then maybe another solenoid to "shut off" the tank when you need lockers in a hurry.  As for tank mounting, the only location I have seen that I like is underneath the rig on the opposite side of the driveshaft as the muffler.  This is where I will be mounting my 2 gallon tank.  Here is a pic of said location.  May need play with the mounting location to accommodate your long arms but there are no issues on the LJ.

Thanks Kris!

kris_olof said

I ordered a 2.5 gallon Viair tank and will probably mount it where Kris recommended. My long arms aren't in the way. My question is, if I'm running two air lockers and I also use the system to fill my tires do I need an in and out air line to the tank as shown above or can I just put a tee inline and run one leg to the locker manifold and the other to the air tank? In other words, since my tank is just there for additional compressed air capacity, can I just run an air line to it and not have an outlet? Should I have the tank isolated by a solenoid or have it gated manually so I can shut the line to the tank? Since the tank has six ports I will probably run two lines from it with quick disconnects filling tires. I would like to set it up properly in the first place and not have to change something later so any other advice or recommendations are welcome.  TIA!

Here is my plan for the 4runner... which sounds very simillar to what you are planning out, Jeff. And may help with where you are at currently...

Swapping the ARB Mini for the twin ARB, using the existing wiring for the switches, and like Kris said, connecting them via the ARB wiring harness connector. Your locker solenoids are just a 1/4" M NPT threaded into the manifold attached to your current ARB mini. You have 3 options... you can take a grinder to your ARB mini and remove the manifold and re-use it, or you can setup your own manifold, or you can buy a new manifold from ARB. I personally am going to be setting up a 6 port manifold from Grainger in my engine bay. Those 6 ports will be: 1, connection for airing up from the front. 2, front locker. 3, rear locker. 4, gauge. 5, output to tank. 6, plugged, extra.

The tank will be setup with a T. On one side of the T will be the input to the tank from the manifold. The other side of the T will be an output to a rear air hose connect for airing up from the rear. If you wanted to shut off access to the tank (maybe because you want your lockers to engage without having to fill up your tank?), then you can easily add a ball valve at the T on the input side of the tank that comes from the manifold... Or you can add a ball valve at the output of the manifold that goes to the tank... just depends on if you want to crawl under the rig to shutoff the tank, or open the hood. Now that I am thinking of it, I will probably be putting one at the manifold, so I just have to open the hood.

Now that my wheels are spinning... There is another option... On the line that I will be running from the manifold to the tank, I will be adding a T and having a small air line come into the cab so that I can have a gauge inside the cab to monitor the system. If you wanted to get fancy, instead of running a T, you could just run that air line into the cab and have an in line gauge and ball valve inside the cab, and then have it continue out to your tank. If you wanted to be really fancy, you could do a solenoid and setup another switch in the cab instead of using a ball valve. This would allow you to shutoff your tank from inside the cab.

Here is the manifold I will be using in the engine compartment:

https://www.grainger.com/product/PNEUMADYNE-INC-5-5-8-x-1-1-4-x-1-1-4-Black-2KHC2

Thanks for all the great information guys. I had to pull my original wire harness because the ARB twin uses different connectors and because the solenoid wires are incorporated into the harnesses. Turned out to be a whole lot of work. I had to remove the bar of my Hard Rock roll cage that goes just above the dash in order to remove the bezels that allow access to the switches and wiring harnesses. That required removing my safari top. I finally got the new wiring harness through the firewall and got the switches wired. Now I need to wait for the M.O.R.E. ARB TJ compressor mounting bracket to arrive before I can do too much more.

I haven't connected the other wiring harness to the battery yet. The problem is think I'm out of places to connect the wires, which are fairly large, to my battery. I though I had seen some type of device to enable more connections to be made to the positive lead of the battery. Does anyone know what I should do or where I can purchase the necessary items and parts to do this?

Check out bluesea...

https://amzn.to/2xiOxDf

Rated for 100 amps total, 30amps max per circuit. They also have options with ground busses built in. I think the twin ARB pulls upwards of 45amps peak... so you may want to just hook that straight to the battery and move some of your axiliary items to the Bluesea.

Would these work? https://www.amazon.com/InstallGear-Positive-Negative-Battery-Terminal/dp/B00NQ7U982/ref=pd_lpo_vtph_107_bs_t_1?_encoding=UTF8&psc=1&refRID=G25XQ52X3RNBVD7K97GV

Another thing you could do is swap out your group 34 battery for a 34M and get the marine posts with nuts for high amperage accessories. (That is what I did and makes accessories super easy to add)

The more I do, the more questions I seem to have! I have thought about a variety of set up options. Here are a few in order sequence of components:

Option #1:

Compressor>ARB manifold (locker solenoids attach to manifold)>Tee with two legs:

Leg#1: Front quick disconnect for filling tires

Leg#2: Ball valve shut off (to isolate flow to tank)>Tank>Rear quick disconnect for filling tires (alternatively I could also run both the front and rear quick disconnect lines from the tank which would enable me to be able to shut the tank and both lines off with one ball valve )

Option#2:

Compressor>Tee with two legs:

Leg#1: ARB manifold (locker solenoids attach to manifold)

Leg#2: Ball valve shut off (to isolate flow to tank)>Tank with two legs exiting tank:

Leg#2A (from tank): Front quick disconnect for filling tires

Leg#2B: (from tank) Rear quick disconnect for filling tires

I have considered a few other variations of the set up as well. My primary question has to do with the plumbing. I purchased an air source relocation kit from Viair thinking that I would use it to plumb the air to the tank. However, it is a 1/4" OD line so I'm concerned that it doesn't have adequate air flow capacity when filling the tank and airing up tires. In option #2 above I would be bypassing the ARB manifold and could use larger diameter fittings and hoses from the compressor to the air tank for filling tires. My concern with option #1 is that everything would have to flow through the smaller diameter braided hose leading from the compressor to the ARB manifold before going to the larger diameter fittings and hoses for the tank and tires. What are your thoughts on this?

My other question is what type of larger diameter hose should I be using to plumb the tank and from the tank to the quick disconnects? I'm concerned that standard air compressor hose will get brittle, crack and fail. Is there something better?

It is the ID of air line that determines the flow capacity. Assuming it shipped with standard air brake DOT approved nylon tubing you are looking at 1/4" OD with .04 wall thickness for an ID of .17".  Assuming 15ft of this hose at full pressure (90psi+) it will flow 3.55cfm which is slightly restrictive.  However at 30psi, once the air tank is drained, it will only be flowing 2.24 cfm which is less than half of the ARBs published flow rate at that pressure. I would look for a 3/8" or 10mm hose and fittings.  The short braided hose shouldn't have a significant impact on flow but I will let you know if I notice any difference in tire fill times after I switch mine from direct chuck to tank based some time next month.

Here are some amazon links:

http://a.co/d/hMlvL91

http://a.co/d/6hP0xi7

You could also run a normally closed solenoid in place of the ball valve and use a switch but note that you will need one with 1/2" NPT ports to get one with a large enough valve size to not restrict air flow.

I called WFO and the guy recommended using 3/8 black ABS tubing. He said it is like the ARB blue air hose on lockers, only larger. He said it is what trucks use for air lines and that it can be found along with the fittings in the truck area at Napa Auto Parts. I'm going to go there and check it out later today.

After going to the auto parts store I ended up buying 3/8 DOT air brake hose. I think the guy at WFO might have been referring to nylon hose when he told me ABS hose. In either case, the 3/8 air brake hose has a 900 pound burst rating according to the clerk. It looks similar to fuel hose because it is fiber reinforced. The fittings slip in and are held on with hose clamps. This hose will be easier to route than nylon hose and is less prone to damage from heat and kinking. I don't know how it compares to regular air compressor hose but it seems thinker and stiffer so hopefully it will last longer than compressor hose.

Jeff_R said After going to the auto parts store I ended up buying 3/8 DOT air brake hose. I think the guy at WFO might have been referring to nylon hose when he told me ABS hose. In either case, the 3/8 air brake hose has a 900 pound burst rating according to the clerk. It looks similar to fuel hose because it is fiber reinforced. The fittings slip in and are held on with hose clamps. This hose will be easier to route than nylon hose and is less prone to damage from heat and kinking. I don't know how it compares to regular air compressor hose but it seems thinker and stiffer so hopefully it will last longer than compressor hose.  

Cool! Any chance you can bring a scrap to the next club meeting so I can see it in person? (or better yet drive the jeep?)

kris_olof said

Cool! Any chance you can bring a scrap to the next club meeting so I can see it in person? (or better yet drive the jeep?)  

Hopefully I can bring a scrap of the hose and drive my Jeep to the next meeting. I got the tank installed and ran an air line for the rear quick disconnect today. This project has taken longer than expected for several reasons. I ordered the compressor, some accessories and the compressor mounting bracket from Northridge 4X4 on Sunday September 9th. I got the compressor and accessories in two days. The mounting bracket for the compressor was to be dropped shipped from the manufacturer and is supposed to arrive tomorrow after I called and pestered them to ship it yesterday. Hats off to Northridge for their great service and quick shipping!

Since the mounting bracket was delayed I decided to install the wiring harness for the compressor and the tank first. The benefit of the delay was it gave me a lot more time to try and figure out how the heck to design and install everything. Thanks to the advice from you and Tyler I think it will turn out much better than had I just jumped into it right away. I appreciate all the input!

I installed the ARB twin compressor using the M.O.R.E. bracket. Because there is no place close to the compressor to install the ARB manifold using the short braided hose that was supplied, I mounted the manifold on the driver's side inner fender and ran a 3 foot Viari braided hose to supply manifold. The manifold has two ports, one for supply from the compressor and the other a discharge for filling tires, etc., plus two ports for the locker solenoids.

On the discharge side I installed a ball valve so that if my onboard air system ever developed a leak I could shut if off and still have my lockers function. As a result, I will not have any rubber hoses between my compressor and my locker manifold. I then installed a tee to run air to the 2.5 gallon tank mounted under the vehicle. The other leg of the tee will go to a quick disconnect at the front bumper area. From the tank I'm running another line to the rear bumper for a quick disconnect for filling tires. Below are a few pictures of how I'm setting it up. I still need to install the rubber hose from the manifold to the air tank. I also ordered another 3 foot Viair braided hose and will run that to the front quick disconnect instead of running rubber hose to that location.

Looks good Jeff. Nice work.

Looks good!

I just spent 5 hours yesterday mounting my twin arb haha. There arent any premade brackets that put the compressor where I wanted it in the engine bay... So I had to relocate a bunch of things and re route every single wire to my battery lol

It looks ugly... I am going to need to go in and redo my engine harness and lengthen all the wires there eventually. But it is in! Electrical is all done, mounting is all done, now to setup all the plumbing.

I am using a Flexzilla hose (same thing I use in my MORRFlates). It is good up to 300psi, 1/4" ID, super flexible, never kinks, never gets brittle, 20$ for 50ft, and hyper green!

I am running out of room to put the manifold... so I like your idea of mounting it elsewhere, and will be mounting it on the opposite side of the engine bay on the driver fender most likely. I will also be copying your ball valve at the manifold to isolate the tank 🙂

I will get some pictures once it is all said and done. Need to get it done before barrett lake this weekend! haha

Also... not sure what your plans were, but those barbs you have off the ball valve are marketed as "they dont need hose clamps", but you will want to run them. I have found that, depending on the hose you use, they like to stop holding around 40psi and let go of the hose. So, just throw on a hose clamp on those barbs.

Got mine all done!

I ran into a big time snag... Apparently the older style ARB systems were designed to run at a lower PSI than what the Twin ARB Compressor is designed to run at. And I have the older style system because the guys at ARB said that my old compressor was designed to cycle from 70psi to 100psi. So my solenoids were leaking air and bleeding air out of the system above 120psi as a safety precaution. Well the Twin compressor cycles from 135 to 150 psi... which means that with the solenoids bleeding air, the compressor never gets up to 150psi and never shuts off lol. So I tried to find some new solenoids that were setup to run on higher psi with the twin compressor... missed metalcloak by a few minutes. So I called a few buddies who I will be wheeling with this weekend to see if they had any spares.

Turns out, one of my buddies from Esprit de four has the older style lockers as well that run on lower PSI. He informed me that if you run the older style lockers with the new style 150 psi solenoids and twin arb, that you will just start blowing out seals in your lockers. That;s why the old style solenoids bleed air if the system gets over 120 psi. So, even if I got higher psi solenoids, then I would blow out my locker seals in my dif, and have a much bigger problem. He got around that problem by installing a regulator between the compressor and the manifold.

So... 7:30pm trip to Lowes the day before my 5am wheeling trip to Barrett Lake...

Setup the regulator and was working on calibrating it to 95psi. Once I got it there, the twin arb cycled on and off every 2 seconds because there wasn't enough of an air reserve between the regulator and compressor to stop compressor air spikes from happening when the compressor was on.

So... 9pm...

Either move the regulator over to right before the manifold, and hope there is enough air reserve in 3.5ft of 3/8 ID hose... or dismount the compressor, take it apart and replace the pressure cutoff switch with the switch from my old compressor. Option 1 was 50/50 on working imo... Option 2 was 100% on working if my old switch worked (which it was when I dismounted the old compressor). Option 2 it is...

Took everything apart, installed the old switch, put everything back together, and at 10:30pm, everything finally worked as intended. 5 gallon air tank, twin arb, air coupler in the rear to air up, 2 up front, system shuts off at 90psi, lockers all work.

Time to pack the rig, shower, go to bed, and get up in 5 hours to go to Barrett Lake lol

I will get some pictures up and updates on how it does when I get back on Sunday.

Wow. Glad you got things working in time for your trip.