Ok, so a little project if your on a budget like me.

This will allow many airups and use of air tools.

I purchased a 15lbs bottle from Airgas for $95. This included the gas. I can simply exchange the empty bottle for a full one for $20. It is possible to get aluminium bottles or steel but my local store didn't have one at the time in alum. so I got a steel one. Note I painted mine to clean it up and intend of just having airgas fill it when I need to. You can purchase bottles in 5, 10, 15 and 20lbs. For me the 5 was way too small, 10 was good but might limit use of air tools and the 20 was wider than I wanted. I wanted to keep the whole bottle setup within the width of the wheel wells for the purpose of easy packing of camping gear. Note that if you have time you can also purchase bottles thru ebay for dirt cheap. You will have to watch out for the service life and be prepared to have it tested. I like the Airgas deal as they have already tested the bottles before they give them to you.

A regulator from Cramer-Decker offroad subsidary offroadair for $40. (this is the same reg forund on The Source and other well known CO2 systems)

25ft 300psi hose from Harbor Freight $10. I preferred this hose to the coil style because I find the coils always get tangled.

1 tire gauge from Harbor freight $14

2 Quick disconnects same as these $4

Steel strap from Home Depot plus some nuts and bolts $7

Like me, many of you will probably have some of this stuff as home already. I had the flat steel , nuts, bolts, paint and quick disconnects. You could also skip the air gauge thingy if you already have an pen style gauge.

For me the total cost was approx $150. The cheapest onboard systems with a 15lb bottle without a tire pressure gauge was approx $250. These are very nice.

Here's the final setup....




So I started by making a steel brace that extended from a hole where a tie down clip was located. (there is frame work here to place a bolt thru and by removing the access plate you can reach behind to place the bolt.)


The other end of the steel brace has a groove cut into the end that allows the brace to slide into the rear seat lock


I used some light weight strap that is easy to bend to clamp around the bottle to attach it to the steel brace


and I used the same strap to clamp around the bottle lower down and then using the same strap ran a piece down to floor. By undoing the tie down I was able to bolt the strap and the tie down making a nice supporting strap with a twist to make the starp align with the hole properly



So the bottle is now nicely in place and very secure


Connect the regulator


Add some quick disconnects to the hose and to the pressure gauge


and the system is ready to go

Very cool. I added this thread to the DIY link in the GENERAL section: http://www.toyota-4runner.org/showth...436#post187436

Does the CO2 tank block the bass from your subwoofer?

Good idea!

LOL...yeah probably but when we're away the cargo is is full anyway so the woofer is always covered up. Plus we babble on to each other on the cb's a lot when we're on trails or on the freeway so msuic is not high on the agenda then.

You could always mount it on the other side if you wanted but some would not like that because it would get in the way of the tool locker (which I must admit I never use anyhow). I like it on that side as a small way to balance weight.

Note - I take the bottle out if I'm not offroading. Takes about 5minutes to remove the whole assembly. Two bolts and slide rearward.

Are there any burst discs on the regulator and if so what are their ratings? The reason I ask is that CO2 has a tendency to expand when heated (like say in a hot truck). If it heats up too much and pressure builds up, the burst discs blows and lets the CO2 out. If the burst discs are set too high, then the pressure can build up and something else will need to relieve the pressure (think bottle rocket)

The gas bottle has its own tap that you close when not in use. There is no pressure on the regulator.

Anyone who relies on the regulator to hold back the pressure on a CO2 bottle would be an idiot.

Also, CO2 systems are very common in offroad applications. There are many companies that specialize in CO2 systems for inside your truck. See Powertank as probably the best known.

Finally, CO2 bottles themselves are stored outside in full sun 356 days. The bottles themselves are extremely overbuilt to withstand the psi placed into them.

If you have evidence of problems that you are indicating could you please provide as many of us would be interested. As a reference point, last weekend we went to the Sierras as a bunch of 4Runners.

Here's what each truck had for airing up

1 x 5lb CO2 (Powertank)
2 x 10lb CO2 (Powertank, Source)
1 x 15lb CO2 (mine)
1 x air compressor (Pep Boys style)

CO2 is a very common system and is used widely for air tools in breakdowns on the trail.

The explanation of my system above is how to reproduce the commercially put together system. The only difference is the mounting, and that I have higher psi hose.

Cheers
Mark