ABR Twin On Board Air !EXPLOSION!

yes

 

Not if they are both froze closed.

 

True, but for this instance the temps had not been freezing in a few days and I had used the compressor the day before and it worked/sounded proper.
I had this problem too https://www.tacomaworld.com/threads/arb-air-locker-solenoid-leaking-gear-oil.739344/ the failure might be related to the differential fluid getting past the seal @kmorgan3
I’ll get a video of the compressor running while it’s in the off position today and post it up.

 

Just a thought but maybe the constant power is a fried cut off switch. Not sure how I would go about testing/checking that, my electrical skills are lacking.
I think the air leak is in the center manifold...

 

Update; Switch ON in the cab cooling fan runs and the passenger side cylinder operates, when I reconnect the driver's side cylinder it cycles, however, the air is leaking from the drain at the bottom center of the unit...

 

Pulled it out of the truck, visual inspection of internals didn't tell me anything obvious. Guess I just send it to ARB for service

 

How do you test the pressure switch?

 

Damn, luckily it didnt damage anything major and the hoses / fittings were able to contain the parts from flying all over the place.

I bought an ARB single second hand and did a full tear down just to make sure it was all good before I installed. Mine had a long bolt holding that expansion tank together. Not some janky all thread coupler like yours had. Not sure if that might be a limitation of the dual? But I would say if possible getting a long bolt to fit is the way to go. Possibly even stainless (which I should have done). Any who has a compressor in their shop knows they accumulate water from the atmosphere which needs to be drained off. Unfortunately for these little compressors all the water ends up rusting everything thats steel.

 

These compressors do have a safety blow-off built into the compressor head. Its a small rubber ball and spring assembly held captive by a hollow hex. Being rubber (or whatever it actually is) I would be surprised if that 'froze' shut. There is a slight chance someone could have over tightened the hex holding that in place, which would raise the release pressure way up.

 

Damn! do those things not come with a warranty?? For the price, I`d expect it to be pretty much bulletproof.

 

There should be a pressure switch that cuts power before a pop-off valve kicks in. Ie pop-off is the last safety resort, and something else has failed first for you even to get to checking that. That was the point I was trying to make.

 

I ordered a pressure switch.
Still waiting to hear from ARB after sending an email to Tech Support.
I am going to call again today too.
What's strange is that the relief valve (1 or 2) did not release the overpressure, which resulted in the differential manifold failure.

 

Oh yeah, for sure. I was just clarifying that these do have one. (At least the single does I haven't actually seen a dual in person)

Personally I think OP just had bad luck with a failure of that corroded all thread joint, not an overpressure event.

 

This was a pleasant surprise... ARB is sending me a new manifold, 2 relays, and a pressure switch at no charge for equipment that is well outside of warranty. That's about $140 retail.

Their response;

Hi Billie,

I apologize for the delay. I'm sorry to hear about this. We will be sending you new relays, a new pressure switch, and a new manifold kit. It was most likely a failure of the relays and/or pressure switch, but the manifold bursting is something I have never seen before. Also, it looks like there was some rust in the manifold, so there must have been some condensation due to air staying in the manifold after use. We recommend expelling the air from the manifold if it will not be used for a while.

 

Got the parts today and made the repair. What a PITA…small space to work and everything has to be perfectly aligned. Add in not too much extra lead on the electrical components and I had a exercise in patients this afternoon. Other than a louder actuation sound engaging the lockers everything’s working as it should.
One question for those with the same set up, how often does your compressor cycle to maintain pressure. Mine runs about every 40 seconds. Seems high to me but maybe not. I did spray everything down with soapy water. No leaks in the compressor components or attachments.in the engine bay.

 

Every 40 secs is a leak somewhere. I can leave mine on all day on the trails with no cycling, and I have remote connections with more lines then usual. Follow all the lines back to the diffs, while the compressor is cycling, if the leak has enough pressure you will hear it. Soap up the bulk heads fitting and the fittings at the compressor as well. Pay close attention to where the air lines come real close to the cats and look for damage. If all that checks out, the actual compressor may be losing pressure before it gets to the manifold. What is interesting is that the unit is reading pressure as it keeps cycling.

Good luck, I find it super annoying when I just want things to work. But it happens all the time.

 

No cycling on my twin either. I used Loctite 545 ($$) as sealant though.

 

If you didn't, I'd use this on all the threads

 

I have in the past...but it was late, I had a handful of beers and a couple of whiskeys in me. Soooo Teflon tape was better than nothing

 

Yeah the teflon tape will leak because of the pressure