OBA -> On Board Air Mega Thread & BS

It's no longer under warranty.

I just ordered some 40 Amp circuit breakers to replace the fuses.

 

Recently tested a 4 lbs tank in the bed to see if it would help filling the tires quicker. It did not. Ended up with a power tank for quicker fill ups.
After this last wheeling trip it was worth the expense and trip to get it filled. It's so much faster.

Pics for fun.

 

To get refills it needs a yearly visual inspection and a hydro test every 5 years based on the date stamped into the neck. Scuba outfits(or wherever you’re getting it filled) and fire safety companies can either do this or point you in the right direction.

 

Did someone ask about refills or the 5 year date? The large majority of Scuba shops do not fill CO2. In my area ir's welding supply shops, fire suppression shops or Gas companies that fill CO2.

 

AFAIK all pressure vessels require the retest after the 5-year date to get fills. You’re right, scuba shops don’t do CO2 but some Paintball retailers do and I’ve seen it at a lumberyard. Because of inconsistent CO2 supply I’ve since switched to HP air and bought my own HP compressor and have a few bottles I can fill.
* Keep your tank shaded, there’s a burst disc that will blow if you leave a black tank full of either CO2 or HP air in the sun. It’s easily replaceable but you can’t refill the tank until it is.
If you’re asking whether they check date they’re supposed to and were consistent about it when I needed fills.

 

CO2 is way more expensive to fill. $25 for a 5lb tank. Scuba air is $6 for an 80. Burst disks are almost 2x rated fill pressure. You'd need to get a tank scorching hot to blow one. I've been diving 35 years and never saw a burst disk go due to heat. Corrosion, yes, but not heat. Pure oxygen is only $0.40/cubic foot which is still cheaper than CO2. I also dive trimix. Helium is currently $2.00 per cubic foot.

 

A CO2 burst disc can definitely pop if you leave the black tank in the sun because it’s liquified under pressure and heat will convert it to gas raising the pressure more than heating a gas alone will. Had it happen and the conditions weren’t even that extreme. I’ll grant I haven’t seen a scuba tank blow a disc but mine aren’t black and I don’t use them in extreme heat, just marine environments. If a disc did blow on a trip both that and a refill would be readily available. That wouldn’t be the case for an air bottle used to air up tires miles from anywhere so maybe a little more care isn’t out of order. It’s definitely in order for a tank filled with CO2.

 

Sounds like a good reason not to drive around with CO2 tanks in your truck.

 

Been there done that, and is why I always have "silver"tanks or non painted tanks.
https://preeceproducts.com/source-co2-systems

 

It’s certainly “a” reason though it’s not a hazard. When a burst disc goes it’s just a leak you can’t stop. Everything has pros/cons. Might be harder to share a fixed quantity vs slower but more available compressor(until said compressor shits the bed). As with gas I don’t run my tank dry but even if I did a bike pump could fill my air bags. Pick your poison and prepare for adversity. I just don’t leave them in the sun anymore.

 

Alright.

I bought my Tacoma in 2017. At the time I installed and ARB Dual compressor.

Since then, I have replaced it two times. They keep failing. After a while, it will kick on but not kick off. It keeps pumping until the pressure valve blows on the air compressor and keeps going. Thing is, it won't let me shut it off. Even if I flip the switch inside the cab, it still keeps running. I finally had to pull the two fuses on the power cables under the hood to get it to stop.

This is the third ARB Dual that has been in the truck in 7 years AND THEY KEEP DOING THIS SHIT! Previously I tried tearing the compressor apart and replacing the pressure switch and the relays but that didn't seem to help.

WTF is wrong with these things?

 

As expensive as they are there’s not a lot of competition especially considering the mounting options to be had.

I’d suggest upgrading the wiring harness, fuse holders, and relays to reduce heating at contact points (thicker wires and heavier duty relay and fuse contacts can do this).

Another 100% duty cycle option would be a pair of Vair 450C units but this won’t be as compact or quite equal the output.
If it’s mounted in the engine bay consider moving the location to one that doesn’t preheat the unit since heat is the primary cause of degraded performance. Beyond that you’ll probably have to spend a couple g’s on an oil filled rig or go to canned air which is great but is a fixed supply.

A rant is fine for getting things of your chest but in the absence of other options (ie. ARB improving their product or another viable product) all that’s left is doing what you can to take care of it.

 

It's beginning to sound like another brand of compressor will have to be purchased.

 

It’s a choice to be considered. ARB is expensive enough that having to pay even more for upgrades that shouldn’t be necessary is annoying to say the least but if no one else offers the performance and convenience it offers even with that additional cost what do you do? All I can suggest is optimize whichever brand you choose to get the most reliability out of it.

 

After the 2nd one it seems more like wiring or set up to me. I would take a deep dive into the wiring and redo it start to finish. How is the wiring run, is it in the same spot as the previous two? If it is, change how it's wired, look for tears in the stalk were it could be making contact. I don't know your set up, but the AC drain hose is a large opening in the fire wall with a grommet that is a perfect spot to come into the cab if your compressor on the passenger side mount.
3 bad units in a row seems off. Not saying it cant happen just really odd. I have videos on my channel on running it through the AC drain hose opening in case you are curious.

 

Sorry to hear you're having issues.
I can see how you might not want to try another one.

I got the dual arb around April this year and its running fine.
I'm using their wiring.
Running ss air line right off the compressor, heard this was important.

Got a buddy who got one about a month before me and his is running fine too.

 

I don't want to burst your bubble, but wait two years and see if it still works.

 

That’s good news. There have been a few posts recently regarding failure of the fuse holder wiring due to excess heat which could be caused by bad crimps. Failure of a relay can either be excess heat or corrosion if the relays aren’t sealed. It’s unknown what percentage of ARB compressors suffer from defects but it’s almost guaranteed there will be some. The question is whether to bother with making changes to the install to lessen the likelihood of failure or go another route. As convenient as an engine bay install might be with ready made brackets I think I would move it to a cooler location since anywhere else on the vehicle would drop the starting temp 75-100 degrees. At that point upgrading the harness is a no brainer. I would do that with any compressor choice that required sustained operation(anywhere duty cycle comes into play) as most off-road installs seem to do. If it’s just lockers or lift bags and not fills then it probably doesn’t matter.
Another possibility would be a self imposed duty cycle to allow the unit and wiring to cool but that negates one of the main reasons for going with an ARB dual.
Changes may not be necessary but it’s the kind of thing you only find out after it fails. 3x running or even 2x would get me on board with doing something about it. Just reading about issues with these trucks is enough to inspire quite a number of preventative mods so it’s not a new idea.

 

In my previous one, I took the compressor apart and replaced the relays. It worked for a while and then quit again.

 

I can buy one of these for half the price of a new ARB.

$315 VIAIR (20007 Air Source Tank , Black

https://www.amazon.com/VIAIR-20007-...mzn1.fos.17d9e15d-4e43-4581-b373-0e5c1a776d5d