CO2-operated locker

[Nimrod]

There's nothing technically complicated about rigging up a CO2 bottle to operate a pneumatically-actuated locker, but when I first decided to do it I looked for a thread and couldn't find one. So I figured I'd go ahead and post this up to show how I went about it.

By way of background, my XJ had a cable-actuated Ox Locker in the front axle (a D30) when I bought it. That cable eventually failed from rubbing against a tire. I replaced it and had a similar issue and another failure. I replaced it again and it failed by being routed too close to the engine block without a heat sheath. So I decided to try a CO2-actuated setup instead. Ox was not able to modify my old diff cover to accommodate an internal pneumatic actuator, and I didn't want to use one of their external "air" piston type actuators because to me it just looks too vulnerable to rocks and such, so I ended up buying a new Ox diff cover.

I bought a 12 ounce paintball CO2 bottle and an Interstate Pneumatics WRCO2 regulator. After lots of thought and hitting on no better idea, I decided to mount the bottle in the cubby in the cargo compartment, as shown in the picture below. It wasn't easy to find mounting clamps to secure the bottle in place. I finally found some by Googling "fuel pump clamps" or something like that.

I ran the line up inside the passenger-side D pillar to the roof line and then ran it under the plastic trim to the A pillar. I couldn't get the A pillar trim completely off, and didn't want to force it, but I got it loose enough to run the line down the front of the A pillar under the trim. I then fished it down the side of the dash and into the kick panel by the fuse block. It's completely hidden and safe from any risk of chaffing or snagging. So I'm very happy with how this routing worked out. I ran the line along the firewall to the center console, where it connects to a pneumatic switch mounted to the ashtray plate where the PO had originally mounted the cable shifter.

I used the new setup for the first time this past weekend at SoCal Fest and couldn't be happier with it. My front locker has never shifted in and out of lock so effortlessly.

 

[lazyxj]

Nice, any idea how many cycles you get out of a cylinder?

I would consider upsizing to a 10-lb CO2 tank, useful for airing up.
It's so much quicker than any 12-volt compressor and it can operate an air impact wrench.

 

[Nimrod]

According to Ox, a 12 oz. CO2 bottle should yield about 1200 cycles. But I discovered before even installing the bottle that left in a car on a hot day the pressure inside the bottle will hit the 1800 psi burst rating pretty quickly and will rupture the bust disc. So, after replacing the disc and refilling the bottle, I bled a little pressure off as a precaution. (I figure I didn't really need to shift the locker 1200 times in a weekend and can sacrifice a few shifts in the interest of protecting against over pressurizing.) I also bought a couple of prefilled one-time-use CO2 cartridges and an adapter -- all very inexpensive-- and carry those as spares, just in case.

 

[Anak]

I am somewhat surprised that you hit the burst rating, particularly given that summer isn't even here yet.

I have carried a couple of those paintball canisters around in my work truck for years, always with at least one of them filled, and never had any issues. (They make a convenient power source for a trim nailer for small jobs.)

Something doesn't sound right. Maybe a defective burst disc? Or could you have been parked such that the bottle was receiving direct sunlight? (Seems a stretch, but that is one factor that doesn't apply to my situation, given that my bottles are in a metal box where the sun can't reach them.)

Or maybe I have just gotten lucky.

:dunno:

 

[Nimrod]

The bottle was sitting on the black leather passenger seat of my Mini Cooper in direct sunlight on a warm day when the disc burst. Obviously, that was a recipe for expansion. But it did surprise me because I've carried scuba tanks in cars under much more adverse conditions probably on hundreds of days (not exaggerating) without ever busting a disc.

 

[Anak]

Okay.

That makes a little more sense.

I was imagining the problem occurring with the bottle in the installed position, as pictured.

Still, if you consider all the guys who carry around C02 tanks out in the desert, in full sun, and it seems they regard those as reliable systems... I am still inclined to think something went wrong on the manufacturing side of your bottle/burst disc. I would think it should be a reliable system.

 

[Weasel]

I had a similar setup but it worked okay. Had issues with regulating pressure, getting the bottles filled. Places around here would just get weird and not want to refill them. Did have issues with the bottle bleeding off when sitting. Ended up having the seal in the ARB go out and sold it later but would have worked out the issues if kept it.

 

[Nimrod]

Using Tapatalk to reload the images that disappeared from the first post in this thread thanks to Photobucket.

The co2 bottle mounted in the cubby in the cargo compartment:

The pneumatic toggle switch mounted to a plate where once resided the ashtray:

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