ARB twin compressor on the ABS tray in a manual

LJDC

TJ Enthusiast
Supporting Member
Joined
Feb 20, 2023
Messages
231
Location
D.C.
I was eventually able to install the ARB twin compressor on the empty ABS tray in my manual LJ. I thought I’d share how.

1. It will fit under there, laying flat on the tray. You need to angle it toward the back of the Jeep, then rotate it, then slide it down. It seems like it won’t fit, and then it does, like a puzzle piece.

2. The ARB twin comes with bottom plate for mounting. The plate has eight tapped holes for metric bolts. Ordinarily you would screw bolts into that plate from underneath. But instead you can take off the plate, screw bolts in from the “inside,” and then reattach the plate: the bolts will protrude out the bottom. I used three grade 10.9 bolts (which I already had).

3. I tried a bunch of ways to match up the bolts to holes in the ABS tray, but nothing was right, because the fit was so exact. Eventually I just inserted the compressor and ground the bolts into the tray, and where I saw the marks I drilled holes. To be honest, after several failures, I was pretty shocked when it dropped right in.

4. Now the hard part: attaching the nuts to the bolts. You can remove the ABS tray, but then with the compressor installed you can’t reattach it. So: If you lay down under the driver’s door, feet facing the same way as the Jeep, you can reach your right hand up into a space to access the underside of the ABS tray. You have to feel around, balance it on the edge of your fingers, and (in my case) swear a lot. I found it less frustrating to have a pile of them, so when I dropped one I could just grab another. I also found that a lot of swearing helped. (I tried removing the fender, but the space was still blocked.) This was the absolute worst part.

5. Once the nuts are threaded onto the bolts, you can grab a handheld ratchet driver and tighten them. This I found to be very satisfying. But don’t drop the tool; it will be a pain to retrieve. Ask me how I know.

6. For extra safety, I added metal zip ties around the compressor and tray. I may remove them later, since they’re not doing much.

7. At the angle I used, one of the intake filters fit fine, but the other (closer to the corner of the engine compartment, where there’s a fat wiring harness) did not. I couldn’t slide the compressor in with the filter on. I couldn’t even score in the ARB right angle elbow, because the wiring harness blocked that too.

So there I installed the ARB relocation tube—just one. I needed a male-to-male coupler, attached to the ARB female-to-barb, which gave me just enough space to screw it in once in place. This is backwards for how they intend, so I needed another coupler to attach the filter to the other right-angle elbow (coming off the hose). I tucked that under some wires and protruding in the corner.

7. Routing the wires is annoying but not terrible. There are a few things to avoid. No big deal. try to keep them off the top of the compressor, which gets hot.

8. Finally, I routed a 1m braided hose into the wheel well and attached the quick-disconnect coupler near the bumper. They make a little cap for it, so it doesn’t get gunked up.

I hope this helps.

IMG_0797.jpeg


IMG_0793.jpeg


IMG_0821.jpeg


IMG_0822.jpeg


IMG_0823.jpeg


IMG_0824.jpeg


IMG_0947.jpeg


IMG_0944.jpeg


IMG_0943.jpeg


IMG_0949.jpeg


IMG_0948.jpeg
 
Oh, I almost forgot: Before you drop in the compressor the final time, open the black cover and loosen the bolt that holds the air outlet in place, which you can than swivel just enough to clear the master cylinder (is that what it is?) when you need to screw in the fitting. So rotate it about an inch toward the driver’s side.

I did not do this in advance, and so I had to finagle the black cover off, and then figure out how to loosen the bolt at a weird angle. So what I’m saying is, it would’ve been much easier to do in advance.
 
Nice job. I did the single ARB on the ABS mount and THAT was a pain in the ass. The twin had to be a really challenge to shoehorn in there.

The stainless leader hose.. Be careful where it passes under the wiring harness (or passed anything else for that matter. Braided stainless will eventually abrade through just about anything it is touching and will get pretty hot as well. Might want to do a double zip tie on those. One around the hose and the harness and a second zip tie around the first between the hose and harness to keep them apart and from rubbing against each other, then snug them up.. not tight, just snug.
 
Nice job. I did the single ARB on the ABS mount and THAT was a pain in the ass. The twin had to be a really challenge to shoehorn in there.

The stainless leader hose.. Be careful where it passes under the wiring harness (or passed anything else for that matter. Braided stainless will eventually abrade through just about anything it is touching and will get pretty hot as well. Might want to do a double zip tie on those. One around the hose and the harness and a second zip tie around the first between the hose and harness to keep them apart and from rubbing against each other, then snug them up.. not tight, just snug.

I was thinking about using wire loom, but I’m worried it’ll melt.
 
I was thinking about using wire loom, but I’m worried it’ll melt.

It will melt. And, depending on how close the harness is to the output fitting on the compressor could leave the braided line hot enough to melt the loom over the harness. You have stainless zip ties.. Do the double zip tie thing with the stainless zip ties.

I am assuming you are familiar with the double zip tie move... On the two positive cables going to the PDC.
2023-03-18 Battery Cable ReOrg 02.jpg
 
  • Like
Reactions: MikekiM
Since you're tweaking the setup, the hole where you brought the hose out through the inner fender liner is a potential failure point. Just keep an eye on it as over time with the hose rubbing the metal something might give.
 
  • Like
Reactions: LJDC
I ended up using this sheathing from Amazon, plus the zip-tie trick above to separate it from the Jeep parts and other items. The sheathing is also between the hose and the fender liner. Good ideas, all. Thank you.
 
  • Like
Reactions: PNW_LJ