I have been running a CO2 system in My Toyota FJ Cruiser for the last 3 years. After each trip the CO2 tank needs to be refilled which costs over $18.00 at the local welding supply store which has started to add up. I’m also am planning on adding an ARB air locker to the front differential.
With these things in mind I decide it was time to add an on-board air system. I decided to purchase a Viair 200psi Ultra Duty system. This system is designed for filling any sized tires and will also work well to run the front air locker.
The installation of the system took over 6 hours and is relatively involved. I chose to use the space behind the rear axle to mount both the compressor and air tank.
I installed the pressure gauge and the control switch in the dash panel in front of the passenger seat. The control wire and the tubing for the pressure gauge are run through the floor and along the frame to the tank and compressor. The control wire and tube are enclosed in wire loom to protect them from wear. I wired the switch to my accessory fuse panel located next to the gauge. The compressor is directly wired to the battery through the pressure regulator.
I welded the compressor bracket to the left frame rail. This location keeps the compressor shielded from most road grime. The tank is mounted to a steel plate that is bolted to the underside of the body.
To provide the compressor with clean dry air I routed the intake tube through the floor and mounted the filter to the left trim panel. I was able to use a heat gun to soften the tubing so I could bend it.
For ease of use I mounted the air hose coupler in the rear bumper using a swivel connector.
Powering the system up revealed a few leaks that I was able to fix by tightening the fittings. The swivel connector also leaks which I will just have to live with.
Look for a functional review after my next trip.










How did you mount the tank to the underside? My tank is in my DO bumper right now, but I want to move it to where you have yours.
My name is Don and I’ve been following your fj adventures for over 2 years now. My computer was obsolete, but just upgraded so now I can respond to some of your material. 1st of all, thank you for this sight. It is very informative to an fj owner. I happened to do a Death Valley trip this past Thanksgiving, and was so excited to read about your Death Valley experience a couple of months later, and the pictures were like reliving that adventure. I had a glitch on that race track road as well, and have been wondering if I should pony up some more serious emergency repair items, and on board air is one that I’ve been researching.
So, is your viair ultra duty adequate for operating air tools, like an impact wrench?
thanks,
Don