Product Review: ViAir Corporation Ultra Duty Onboard Air System (P/N 20001)

Not only is this a product review, but it is the first in a three part series on tire pressure management.  In this article I will review the onboard air system that was installed last year, and in the next I will review a new set of tire deflators.  These will serve as a segue into a more detailed discussion on the how’s and why’s of tire pressure management both on-road and off-pavement.

Got PSI?

About a year ago I installed one of ViAir Corp’s Ultra Duty Onboard Air Systems into the LJ.  My rational was two fold.  Firstly, I wanted the ability to air up my tires in remote locations.  Secondly, I wanted the ability to run air tools when needed.  While there are many options to address the first part, the second necessitated a compressor with a 100% duty rating, a high PSI output, as well as a system with an air tank.  Rather than piecing together a system I opted for an “off the shelf” solution.  Having past success using ViAir brand equipment I put them at the top of the list.  Read on for my review…


Installing a ViAir Corp Onboard Air System is pretty straight forward.  Everything you need is in the kit right out of the box.  The system is flexible enough to mount wherever you need it to go.  The included wires and hoses are more than adequate for most installations but if you were going for something elaborate or very custom you probably already have what you need anyway.  My only bit of custom flair was using an OEM style rocker switch in a spare dash opening to match the other factory rocker switches and then frenching in the included air gauge into the dash next to the switch.

As far as the kit goes, everything you need is here.
Instructions are pretty straight forward.
Wires are well labeled which really helps when you hook everything up.

Included with the kit (p/n 20001):

  • 2.5 Gallon 200 PSI VIAIR Air Tank
  • 480C Chrome VIAIR Air Compressor
  • Tire Inflation Gun with 200 PSI Gauge
  • Dash Panel Gauge with ON/OFF Switch
  • 30ft. Coil Hose with Quick Connects
  • Pressure Switch (165 PSI on, 200 PSI off)
  • Reducer: 1/8” (F) to 1/4” (M)
  • Reducer: 3/8” (F) to 1/4” (M)
  • 1/4” Quick Connect Stud (F)
  • 1/4” Quick Connect Coupler (F)
  • 1/4” 250 PSI Safety Valve
  • 1/4” Drain Cock
  • (3) 1/4” Compression Fittings
  • 20ft. 12-Gauge Wire with Inline Fuse Holder
  • 4” Strip of Continuous Grommet Material
  • Accessory Airline
  • Electrical Connections
Some personal touches.  An OEM style rocker switch labled for the compressor.
I turned the other way as my buddy put the dash piece into the drill press to make the hole for the gauge.
All in all it turned out really well and has a nice “factory” look to it.
This was merely a mockup of where I think the compressor and tank will ride.
It’s been like this for the last year and i have a feeling it will get moved.
There is a spot on the frame for the tank and I might build a small cubby for the compressor when I redo my cargo box.
Use and abuse:
Having my own air compressor has been amazing.  Usually at the off road park I’d have to wait in line to use the park’s air system.  Not everyone is nice enough to wait their turn and sometimes the wait could be an hour or more.  I have a few friends with their own compressors for their air lockers and some can handle airing up tires too.  Sometimes I’d just wait till they were done, but that still required patience.  Now people wait on me.  It’s a nice switch.
Lending use of my air system out to a friend as we air up after some snow wheeling last winter.
Selfish reasons aside, being able to air down and air back up when on overland trips or trail riding was the real motivator.  On the 2015 No Highways Tour I was very limited in my ability to manage my tire pressure appropriately.  There were many times I was off pavement wishing I could air down for better ride quality and better traction (more on that in part 3) but was unsure of my ability to find somewhere local to air back up.  In contrast, on this year’s 2016 NHT I was able to air down whenever I wanted and air back up whenever I wanted.  If a tire got low for some reason I could air it up without having to switch to limp mode and find the nearest gas station.
Airing up my trailer tires to a good pressure after being off pavement most of the day.
Now what’s nice about a 100% duty cycle compressor is it can take the abuse.  When I’m out I not only have the four tires on my Jeep to worry about but I also have the two trailer tires to manage too. Just because they’re on a trailer doesn’t mean they are exempt from adjustment.  Having a strong solid compressor means not having to wait for it to cool down before I finish all six tires.
The numbers:

As mentioned this is a 100% duty cycle system.  ViAir claims the 480 series compressor in this kit will air up a 35″ tire from 15psi to 30psi in just over 3 minutes.  They also claim it will fill the included 2.5 gallon tank from 0psi to 200psi in just over 5 minutes.  To be honest I haven’t timed these to the second to verify, but from my experiences in the field I know I can air up all six tires in about a half hour which seems about right (air up the tank, then work my way around all six tires = 5 minutes plus another 20 or so).

The Good, The Bad, and the Ugly:
I’ll start off and say there is nothing really “ugly” about this kit.  It’s straight forward, reliable, and works as advertised.  With that said, there have been two minor issues.  The first “bad” thing I’ve experienced so far is a slight discrepancy between the in-line air pressure gauge and my pocket tire pressure gauge.  The ViAir gauge on the air nozzle seems to read about 5 PSI higher than my pocket gauge.  I’ve checked my pocket gauge against other gauges and it’s right +/- a psi.  The ViAir gauge seems to constantly read 5 psi high.  No big deal to be honest.  I just air up till the gauge says “40” and know that my tires are at 35.  I periodically check my pressure with my pocket gauge anyway and since I use it more I let it be the standard for the time being.
The only other “bad” thing I’ve experienced was a pressure switch failure earlier this year.  I noticed when airing up the tank in Moab the compressor never kicked off at 200psi.  I shut it off manually till I was ready to air up.  When I went to air up the relay “clicked” and never engaged the compressor.  This was after a long hard day on the trails in the middle of my trip which proved to be a minor inconvenience. Luckily I was able to get ahold of someone at ViAir and after some quick troubleshooting I was able to have them ship me a new pressure switch.  Once I got the new one in the system fired back up and worked fine.
In addition to their great tech support and customer service ViAir has been a great company to work with the past year.  They are not strictly an off-road brand so their social media is an interesting mix of lifted off-road vehicles and lowered street-only vehicles.  Some of the installs on the street/tuner side of things are absolutely amazing.  Sort of makes mine look like the plywood hack-job that it is.  However ViAir does offer some nice pre-made brackets for mounting their compressors which I might have to jump on.
Other Options:
In addition to the Ultra Duty OBA system I’m running, ViAir offers a range of systems from single compressor 200 PSI systems like mine to dual compressor systems, smaller 100% duty cycle single compressor systems, as well as a wide range of parts.
One thing I will mention is if you’re not ready to pull the trigger on a full onboard air system, check out ViAir’s portable compressors:
450P Automatic Portable Compressor (P/N 45043)
100% duty cycle at 100 PSI
Time to air up a 35″ tire from 15-30 PSI is 3 minutes and 30 seconds
The advantage of a compressor like this is it can go anywhere you go.  Going on vacation? Take it with you.  Going for a ride in your buddy’s 4×4? Take it with you.  Need to air up a pool raft in the back yard? Take it with you (although you’ll need a 12v power source too so you’re better off bringing the raft to your 4×4… I digress).  I’ve used a portable ViAir compressor like this in the past 
 which is one of the reasons I sought them out.  The other reason was a buddy of mine had a ViAir OBA system in his Jeep and really liked it.  In the end that’s how these things work, right?  You invest in what works for you and for your friends.  Simply put, my Ultra Duty Onboard Air System works for me.  I look forward to using this system more in the future.
For more information visit:
Stay tuned for parts 2 and 3 of this series of articles on tire pressure management.
Disclaimer: All views, thoughts, and opinions expressed above are those solely of East Coast Overland Adventures and do not reflect any input from ViAir Corporation.