Outdoor Adventure USA

Air Compressors/Airing up and Down

This week we will be discussing the various methods used for airing up and down our tires while off-roading. These methods include portable compressors, on-board systems, CO2 tanks, including onboard plumbing, and hopefully some custom solutions.

Why deflate our tires when off-roading: Simple answer....comfort and traction.

Comfort: The majority of off-road tires are large, "E" rated (10 ply) and inflated to approximately 35-40 pounds or more. This makes for a stiff side wall. When traveling over washboard roads, rutty and rock strewn trails can be quite jarring for both the driver and vehicle. Airing down softens the ride, thus providing more comfort for driver and less wear and tear on the vehicle.

Traction: Off-roading requires maximum traction from your tires. One of the most effective ways is to increase traction is to lower your tire pressure. Simple lowering the pressure can make a difference from getting stuck, making it up an obstacle or spinning your wheels. For example, I was off-roading though some soft sand with 20lbs tire pressure and got stuck. I lowered my pressure to 10lbs and I was able to drive out of the holes my tires were in.



Example 1


Example 2
How do we air down?

There are a multitude of products on the market do deflate tires. They range in price from $20 to $100. Here are a couple of examples.

There many manufactures of deflator kits on the market is a wide range of prices. Below is an example of two.

Tire Deflator Kit Universal Adjustable Pack of 4
Brand: EZdeflator Amazon price $19.95
These screw on to your valve stem and stop letting air out at a predetermined pressure set by you before heading to trail. You have to spend time adjusting each one to your desired pressure.

Made in China
Pros: Ease of use once setup
Con: Once your predetermined pressure is set on each one you can not change it easily.



Staum Tyre Deflators are made in Australia and have been around for 20 years.

Pros: Come preset for 18 lbs pressure are are easy to use.
Easy of use
Cons: Amazon Price $99. Pressure can be changed but not on the fly.

Here are a couple of pictures of a different type of deflator. These offer more functionality. they give you the ability to deflate your tires to different pressures needs change.

ARB Tire Deflator Kit made in Australia. Amazon rice $54.

Pros: Easy of use. Unscrews valve stem for quick deflate. Pressure can easily set or changed depending on needs.
Cons: None



AllStop Tire Deflator Kit made in China Amazon price $26.97

Pros: Same as ARB above
Cons: Lower price made in China. Questionable quality.

Again, there are so many deflators on the market that doing research can make your head spin. What you ultimately purchase depends on your budget and how you are going to use them.

Airing Up

After some fun on the trail we need to air up our tires. Again there are a multitude or options out there to inflate you tires. There are portable ones that connects you your battery. There are CO2 tanks, onboard compressors with tank similar to what contractors use and there are onboard compressors mounted in the vehicle.Warn even sells a winch with a compressor.

Portable Compressors

Portable compress are ones that attached to battery and you move from tire to tire for inflation. These came in various prices, the less expensive ones have short duty cycles and the more expensive ones have a higher duty cycle and some have 100% duty cycles.

As the saying goes "You get what you pay for". For example, when I started off-roading a well meaning friend suggested I go to Walmart and purchase one of their compressors. Well the compressor was only able to fill 2 tires until it died. I exceeded the duty cycle. I was able to return the compressor. I then invested in a compressor from 4Wheel Parts with a higher duty cycle which I still have today.

Here are a few compressors.

For fun here is the Walmart compressor.

Price: $32.99
Pros: None
Cons: After 10 to 15 minutes let the compressor cool for same amount of time (51% duty cycle.


Mean Mother Compressor Made in Australia.

Price: $202.41 at Dirty Parts Off-Road
Pros: Well built. From their website "Reliability in an Air Compressor that it won't break down when you need it most. You just don't find this these days" Company has been in business for over 50 years.
Cons: Price

ARB Portable Air Compressor made in Australia

Price: $412 from ARB USA
Pros: Well built. Thermal protection. Over pressure protection. 100% duty cycle. Comes with own case.
Cons: Price

Viair Portable Air Compressor Model 400P

Price: $415 on Amazon
Pros: Well built. Compressor is rebuildable. Thermal protection. Automatic shut off function. 33% duty cycle at 100lbs. Comes with own bag.
Cons: Price


Portable CO2 tank

Price: $681 at Dirty Parts Offroad
Pros: Fast filling up tires. High pressure tank can be used to seat tire beads. Tanks can be purchase individually or as kits like this one.
Comes in multiple sizes. 2.5lb, 5lb, and 10lb.
Cons: Price. Finite numbers of tire inflations before needing to refill tank. Can become missile in accident if not properly secured.

Onboard Air Solutions

Once again there are so many different types of onboard compressors. Some of them come from the same companies that make portable ones.

There are also mounted CO2 tanks.

Onboard systems require the compressor to be mounted somewhere in the vehicle. This could be in the engine compartment, inside the vehicle or outside. They also require purchasing or building a mounting solution as well as installing wiring, and the hoses (plumbing) to inflate your tires.

Here are a some onboard compressor options.

ARB Twin Compressor

Price: $616 at 4 Wheel Autoparts
Pros: Well built. 100% duty cycle. Comes with electrical wiring loom. Over pressure switch. Brushless cooling fans.
Cons: Price. Has air filter that needs to be cleaned if mounted outside the vehicles cabin. Additional cost to install and run plumbing.


Twin ARB mounted on Jeep. Here you can see that they connect an air hose to inflate tires.


Viair Hard-Mount Compressor for tires up to 35 inch.

Price: $274.50 on Amazon
Pros: Well Built. Duty Cycle: 33% @ 100 PSI. Thermal overload protection. Vibration Isolators and mounting hardware.
Cons: Price again. Has air filer that needs to be changed if mounted outside vehicle cabin. Additional cost to install and run plumbing.


Viair mounted inside cabin.

Smittybilt CO2 tank and holder for mounting in vehicle

Price: Tank $381.99. Holder: $91.99
Pros: Fast filling up tires. High pressure tank can be used to seat tire beads. Tanks can be purchase individually and in different sizes. 2.5lb, 5lb, and 10lb.
Cons: Price. Finite numbers of tire inflations before needing to refill tank. Can become missile in accident if not properly secured.

Place Holder

Please excuse the dust. This FJ is not a mall crawler.

My custom installation

I decided that I wanted an onboard system that was permanently installed and provided an easy way to deflate and inflate my tires. I also wanted the flexibility to set the pressure according to the environment I was driving in.

I decided on a Viair compressor because of it's 100% duty cycle and reputation for being a quality product. After have one compressor die I was also looking for one that could be rebuilt. Since Viair is about a 30 minute drive from my house, it tick all my boxes.

As you can see from the picture (same one from above), I built a custom platform and mounted it to a shelf inside the cabin. This also protected the unit from the elements and having to change the filter more often.

Since the compressor needed a 30 amp circuit I research 30 amp switches and relays. As a cost savings, I ended up installing an inexpensive starter solenoid for older cars. I ran the air hose and electrical wiring from the front of vehicle through the frame to the rear of vehicle where you can see it passing through the plastic shelf. The air hose connected to a manifold in the engine compartment.

Connected to the manifold you can see the hose on the right side of the compressor. The 2 smaller black hosed go to the front and rear hose connectors for airing up and down. The valve is used to deflate the tires and the gage is for setting the pressure.


From the manifold the black hoses run to hose connectors on the front bumper and inside the backdoors of my vehicle. From these hose connectors I attach the yellow hoses (below picture) to run to tires.


Here is a close up view of the bumper hose connector.


After several years of use here are my pros and cons.

Pros: Easy of use. It is really easy to deflate all of the tires at the same time to the same pressure. The same holds true for setting the inflation pressure.

Cons: It takes a while to inflate the tires. In fact it takes me about the same time to inflate all my tires at the same times as it takes someone with a portable compressor moving from one tire to another. This makes sense when you figure that I'm filling 4 tires at once and they are filling one at a time. Same amount of airflow as the other compressors.

I wonder if I increase the size of my black hoses if I'd get more airflow and thus less time. It works so why spend the time.

AIR IS FREE, BUT DELIVERING IT IS NOT

My first air compressor coincided with my first 4WD vehicle, a '93 Chevy Suburban. At that time, it was a portable unit that used the Sub's 12v volt power port (cigarette lighter plug.) It was slow and got really hot by the time it filled the 4 BFGs, but it worked. Oh yes, few people asked to borrow it. Like so much of what we do, time, experience, and our natural tendency to upgrade just about everything, finally ended the portable air compressor. With a new vehicle came the need to fill even larger tires, with greater speed, and the ability to do the same for other vehicles.

While my original intent for a new compressor (on board, this time), has been to use it for my off road 4 wheel drive trips, it has morphed into much more. Neighbors who know of my compressor have asked for multiple fil-ups, kids in the neighbor hood have used it to fill bicycle tires, adventurous Ham Radio users have used it to fill tanks to launch a variety of ropes into trees to string antennas, family members have used it to fill their 2WD vehicle tires after I patched the leaks, strangers on the trail have asked to use it, and its even been used to fill the occasional party balloon. Oh yes, I use it on the trail myself.

It’s been too long for me to remember exactly when the new air compressor was installed, but based on my posts in other forums, it was somewhere around 2004. After a great deal of research, as well as reading as many articles as I could find, I finally settled on an Extreme Outback compressor. In the 18 years that it has been a part of my 4WD, it has NEVER failed or stopped working, and aside from filter cleaning, it has never required any maintenance of any kind. And, in those 18 years, it has filled countless tires. When a new 4WD vehicle arrives in my driveway, it will again be equipped with an Extreme Air Compressor.

Source: Extreme Outback, https://www.extremeoutback.com/product/ ... ompressor/

They say this about the compressor:

The ExtremeAire High Output 12 Volt Compressor is setting the standards for high capacity compressors. By utilizing a 3/4 horsepower fan cooled motor, overheating is a thing of the past. Designed to fill the largest 4WD tires or the highest-pressure RV tires, this unit can fill tires continuously with no fear of motor burnout. With a 150psi continuous duty working pressure (200 psi max), you can fill air tanks and run impact guns to dismount and mount wheels easily. For clean air in the dirtiest environments, the ExtremeAire uses a USA made metal air filter with a replaceable element. In addition, the fan shaft has a sweeper seal to keep dirt and debris out of the motor and brushes, at the same time, allowing moisture and condensation to escape. The ExtremeAire is permanently lubed with sealed bearings so it can be mounted in any position making installation much easier. Every ExtremeAire utilizes stainless steel fasteners for a long and trouble free life in the highest vibration applications. Uses for the ExtremeAire include 4WD, RV, Agricultural, Construction, Motorsports, etc. No other 12 volt compressor has the speed, continuous duty cycle, output, pressure rating, and reliability that the ExtremeAire can deliver.

Tech Specs:

– Continuous duty fan cooled motor
– 3/4 horsepower motor
– 49 amp draw @ 100 psi
– 1.5 cfm @ 100 psi
– Continuous duty up to 150 psi, Max pressure 200 psi.
– Can be mounted in any orientation
– 14″ long, 6″ wide, 9″, tall

The Extreme Air compressor is permanently mounted in the H2 on a platform located at the rear of the vehicle, and it shares this space with my second battery (more on the net.)


Located also at the rear of the vehicle, just inside the rear door, is the on/off switch:


The Compressor outlet is located in the rear bumper, in a welded recessed stainless steel enclosure, protected from the elements with Line-X:


The set-up with the air hose attached, capable of reaching all 4 tires on the Hummer.

I'm looking forward to the Net.
Please check me in.

WD6USA

Please check in -

John - KN6VL

Bruce - KD6GCO

Hello all,

Much of this has already being discussed. Nonetheless, here are some pics of the installation I use.

I started with a Viar 400P It worked okay but only provided 2.5 CFM and is rated at 33% duty cycle. I was also tired of unpacking, connecting to the battery and running the pig tail hose... You know the drill. You can install the Via and I like the compressor. It would work best with a tank.

I finally settled on the ARB twin and installed it in my Jeep TJ as shown. The only drawback is the cost. they are a little pricey but they work very well. I am embarrassed at how dirty my Jeep is in this picture but it has not beed cleaned since my last outing!
I then plumbed it up to a quick connect located at the front of my Jeep just to the right of my winch.
Finally, I installed the ARB switch into a location next to the utility switches that I use for my off road lights.
The last thing I did was to make a custom air hose using ferrules and lock on air chuck connectors.
The ARB is capable of 4.65CFM @ 29ps and it is rated for 100% duty cycle. I run tires fully inflated at about 32 psi so using the hose to fill two tires at once made sense for my application.

Final note: The ARB was actually a close alternative to a great option... The old York AC compressors out of an AMC or older Ford is a really good option for onboard air. The York A/C compressors are the only Air Conditioner compressors that I know of that are not lubricated by the freon. They have oil lubrication that does not rely on the freon. for this reason they can be used as air compressors. Belt driven by the engine with a clutch and a switch they are 100% duty cycle and put up a lot of CFM. Some are rated at 5 cfm or more and there are York compressors that can crank out up to 10 cfm.

Please check me in: WY6R -- Bob

Please check me in tonight.